The noun αγων (agon) means gathering or encounter, and particularly one for the purpose of competing in sports (a clash, a conflict), or observing others doing so. As we will see below, English doesn't have a proper synonym for this word, but the word "duel" comes very close. Despite its similarity, this word "duel" is not at all connected to the familiar words "duo" or "dual" but rather stems from the Latin word duellom, war or combat, from the Proto-Indo-European root "dew-" to destroy or injure, hence also the Greek δαιω (daio), to burn up, and δυη (due), misery, pain (both unused in the New Testament, but see our article on δαιμων, daimon, "demon").

In modern English, the word duel describes a very serious clash fought by two parties, but in a controlled environment, observed by an audience and governed by an umpire. Our noun αγων (agon) describes precisely the same thing.

Our noun αγων (agon) derives from the verb αγειρω (ageiro), to gather, which isn't used in the New Testament, but which stems from the same Proto-Indo-European root that yielded words like the verb αγω (ago), meaning to lead (hence words like pedagogue and synagogue), the noun αγορα (agora), meaning marketplace, αγρος (agros), meaning field (hence the world agriculture) and possibly also the adjective αγιος (hagios), meaning holy (i.e. gathered and put aside).

Organized sports, competitions and contests are of course the domesticated versions of warfare, and, as the Romans demonstrated with their obscene gladiator games, in antiquity hardly distinguishable from actual combat. That means that our noun αγων (agon) does not describe a friendly contest but very real and brutal torture, with the added nuance of being specifically organized as a source of pleasure for an untouchable audience.

From this noun comes our English word agony (αγωνια, agonia; see below), and the duo protagonist and antagonist. The Greeks glorified domesticated Conflict in their deity Agon, who was understandably thought to be related to Zelos (ζηλος, zelos; zeal) and Nike (νικη, nike, victory).

Our noun αγων (agon) means conflict but with the strict clause of being slugged out in a dedicated arena, where the playing field is limited, weaponry is restricted and an umpire enforces rules. In that sense, it means civilized conflict, or at least a conflict that's allowed to play out within the limits of a dedicated arena. Our word could describe the gathering of clashing combatants, or the gathering of gaping spectators, or both. It could describe the place where this gathering took place (an arena or circus), or the prize (usually a crown) that was to be won by the last man standing.

Our word could signify any general struggle or ordeal, with the understanding that this struggle was not against chance or natural chaos but rather somehow governed by (or perhaps even caused by: Ephesians 6:12) rules of engagement and traces of civilized convention. Our word was frequently associated with a wrestling with words (with either the words as the poet's opponent, or else his obstinate audience). Significantly, our noun was proverbially applied to Hercules, whose 12 labors were known by the word αθλοι (athloi), hence our English word athlete (see further below).

Our noun αγων (agon), civilized conflict, is used 6 times in the New Testament, see full concordance, and from it derive:

The verb αθλεω (athleo) means to contend in games or contests (2 Timothy 2:5 only), hence our English word athlete. It derives from the noun αθλος (athlos), meaning contest in both war and sport, especially for a prize (called an αθλος, athlos). As we discuss above, in antiquity, "games" were barely distinguishable from actual warfare and frequently resulted in serious damages. The main difference between games and warfare was not the seriousness of the engagement but rather that games were domesticated: governed by rules, executed on stages and gaped at by enthused and untouchable onlookers. That this word does not merely describe a friendly game, but any life-and-death engagement is demonstrated by the twelve "labors" of Hercules, which were known by this word.

These words differ from the comparable noun αγων (agon), gathering for a contest (see above), in that the latter emphasizes the encounter, whereas the word αθλος (athlos) emphasizes the effort. It stems from the Proto-Indo-European root "hweh-", which means to storm or blow — violent movements of the ανεμος (anemos), wind, and the concepts of wind and air are of course closely related to ψυχη (psuche), soul, and πνευμα (pneuma), spirit. From this same PIE root comes the noun ατμις (atmis), vapor; see below.

Despite the similarities, our verb αθλεω (athleo) is generally thought to be unrelated to the name Atlas (Ατλας, Atlas). From our verb derive:

The noun ατμις (atmis) means mist or vapor (Acts 2:19 and James 4:14 only). It's closely related to the familiar noun ατμος (atmos), which also means vapor or cloud (hence our word atmosphere). The difference between the two is that ατμος (atmos) describes dry vapors and clouds, whereas ατμις (atmis) tends to describe wet ones. The curious "[wet] mist of smoke" that is quoted from Joel 2:30 presents a noted contradiction, but wet smoke is indeed possible when smoke comes in contact with cold wet air.

Both these words derive from the same PIE root as the verb αθλεω (athleo), to contend (see above), namely "hweh-", which means to storm or blow. It has no derivatives.