The difficult adverb οπισω (opiso) means backwards or after, and is usually followed by a genitive form, and thus refers to the back-end of something. In reference to spatial specifications, it often refers to the back of a thing (say, a papyrus roll), or to the hindermost part of some structure or area, implying that there's also a front or forward or prominent part of these things, which our adverb points away from. When our adverb is combined with a movement it often means back or back again, emphasizing a reversal of the direction of the original action.

In reference to time, our adverb (somewhat counterintuitively) refers to the future (i.e. the time that comes after now). Since the past is known and thus continuously regarded, we humans face the past and the past is thus in front of us. That means that the future is behind us, and we back into it, and a movement in the direction of our adverb results in moving backward relative to our field of vision but forward in time. When Jesus famously told satan first (Matthew 4:10) and Peter later (16:23) to get behind him, he both told them to get out of his present field of concern (get out of my sight), and that he would deal with him later (get out of my past and into my future). Conversely, when Jesus told his disciples-to-be to come behind him, he invited them into the future he opened to them (Matthew 4:19).

Since the sun rises in the east, and the east is synonymous with the past (in Hebrew: קדם, qedem, and in Greek: ανατολη, anatole), the sun moves overhead toward the future. Since the sun is the source of light and life on earth, it symbolizes the Word of God from which all knowledge and enlightenment comes (Colossians 2:3). This in turn means that the common working principle of man's cognitive mind is to be wholly aware of the rising of the sun — when cognition begins and things begin to be learned — until man is mature and stops learning new things and merely applies what he knows, not considering the fact that what he knows is part of a day that will ultimately fade as the sun sets behind him. A person who lacks wisdom will fall asleep as his day fades, but a person of wisdom will see the stars for what they are. In psychology we call this Theory of Mind.

Our adverb οπισω (opiso) derives from the same Proto-Indo-European root "hepi-", meaning on, at, near, which also yielded the familiar element επι (epi) meaning on or upon. It also bears a striking resemblance to the formally unrelated (and unused in the New Testament) noun οπις (opis), which means regard in the sense of an observation, but most often in connection to the deity. This noun was often ascribed to the gods (in the sense that the gods were regarding the humans), in which case it commonly heralded vengeance and calamities. But it was also often ascribed to men (in the sense that men were regarding the gods), in which case it followed veneration and awe. All this suggests that these words were probably commonly associated with the nouns ωψ (ops), meaning eye, and οψις (opsis), a thing seen, regardless of whether they are actually etymologically related.

In a very similar way, the nouns θεατρον (theatron), meaning theatre, a place to see things, and θεωρια (theoria), a sight or "theory", stem from the verb θαομαι (theaomai), meaning to wonder, and are commonly supposed to relate to the familiar nouns θεος (theos), meaning God and θεα (thea), meaning goddess.

Our adverb οπισω (opiso) occurs 37 times in the New Testament, see full concordance, and from it derives:

The adverb οψε (opse) means late (Matthew 28:1, Mark 11:19 and 13:35 only). As the above, it shares its Proto-Indo-European root "hep-", meaning back or after, with the familiar particle επι (epi), meaning on, and is not formally related to the nouns οψις (opsis), a thing seen, and ωψ (ops), eye. From this adverb derive:

The noun οψον (opson), describes a dish of any sort of cooked delicacy (comprising fish, meat, relish, condiments; see οψωνιον, opsonion, below), eaten with bread and wine. The emphasis of our word is on delicacy or relish: in proverbial or metaphorical uses it refers to enjoyment (hunger is the best οψον, opson). Since in Athens, fish was the chief delicacy, this word occasionally came to be used as a synonym for cooked or prepared fish.

It's unclear where our word comes from, but since the most elaborate meal of the day was enjoyed after the work day in the evening, the formation of our word may have been helped along by the adverb οψε (opse), meaning late (see above).

Our noun οψον (opson) is not used in the New Testament but from it derive:

The curious noun οψαριον (opsarion) is commonly but erroneously translated with little fish. It's a diminutive of the unused noun οψον (opson), but in this case, the diminutive does not so much refer to something small but rather something elementary: an οψαριον (opsarion) is an elemental part of the οψον (opson), regardless of its size.

The Athenians loved their fish, and an οψαριον (opsarion) was indeed often a fish product (pickled and dried, fried, marinated, or simply a boneless fillet), but technically it could describe any sort of side-dish or cooked food presented on a small plate. In Koine Greek, our word οψαριον (opsarion) had become synonymous with a bit of fish, or a whole small one like a sardine, but processed, preserved or at least prepared fish, which explains its apparent proximity to οψε (opse), meaning late (see previous).

Note that the word that specifically described a whole, fresh or swimming fish, was ιχθυς (ichtus). Our noun οψαριον (opsarion) describes a fish that had been caught much earlier and had been seasoned and fried and was presented as part of a greater meal. See these two words deliberately juxtaposed in John 21:9-11, in a context that declares that in the right hands, a fresh fish becomes a prepared meal, water becomes wine and a sinner becomes a saint — not a mere change of present substance but a change that extends into the past: wine and a fish dish take time to come about, and so does salvation.

Our noun οψαριον (opsarion) describes not an animal but a piece of food that had been painstakingly prepared and produced, like bread. Our word testifies of foresight and planning, it speaks of saving some for later and describes an investment of time and skill, rather than something natural and obtained by good fortune. An ιχθυς (ichtus) is a creature made by God but an οψαριον (opsarion) is a product made by man.

Formally our word is of unclear etymology, and a pedigree shared with οψε (opse) is doubted (for whatever reason). But these words may have been adopted into the Greek language because (a) they described preserved food (food saved for later), and (b) they originally applied to food enjoyed after the workday was completed, with friends and in peace. That in turn suggests that our noun οψαριον (opsarion), came to denote a bit of preserved fish in much the same way in which the word chai, meaning leaf (sla is Dutch for lettuce), rendered its name to the drink called tea, and in turn came to denote an entire meal enjoyed by the English, later in the day.

Our noun οψαριον (opsarion), piece of preserved fish, is used 5 times; see full concordance.

The noun οψωνιον (opsonion) means wage or salary. It derives from the verb οψωνεω (opsoneo), which combines the verb ωνεομαι (oneomai), to buy (not used in the New Testament, which uses αγοραζω, agorazo) with the noun οψον (opson), which is any kind of cooked delicacy that completed a larger meal (see οψαριον, opsarion, above).

In antiquity, food was preserved with salt (see our article on αλς, hals, salt) and note that our English word salary (and sausage and sauce) likewise derives from the Latin word for salt.

In antiquity, slaves would commonly work for food, lodging and security, which suggests that in the Greco-Roman world, a salary was effectively the same as a food stamp, albeit a fancy one. Anybody who was hungry could always scrounge up a meal by fishing or digging for wild turnips or killing a dove with a stone (see our article on the aptly named περιστερα, peristera, dove), but the word οψον (opson) described not merely food but a dish that had been cleaned, cooked, seasoned and presented along with more fundamental victuals such as bread and wine. That means that a salary was not merely money paid to a wage-earner, but rather that what raised a servant briefly to the level of boss, or at least for the duration of a meal.

A salary was a means for a workman to have his equal work for him and do his bidding. It briefly lifted a servant up into the entitled world of the free, until his money ran out and the servant crushed back down to the indentured world from which he had never truly escaped. Only when the servant learned to save his money, and invested it, and so began to be a freeman long before he was actually set free by his owner, he could ever be free. Our noun οψωνιον (opsonion) explains that freedom is not a mere condition but a skill, and that an acquired skill, learned while still in captivity (see our article on εξαγοραζω, exagorazo, to buy out).

Note the deeply theological connotations of these considerations: the word for having to labor for a boss is πενομαι (penomai), from which stems the ubiquitous New Testament word for evil, namely πονηρος (poneros). The polar opposite of evil and having to toil for a boss is ελευθερια (eleutheria), or freedom-by-law.

Our noun οψωνιον (opsonion), salary, is used 4 times in the New Testament; see full concordance.