Abarim Publications' online Biblical Greek Dictionary

ευρισκω

• Together with the preposition ανα (ana), meaning on or upon and which in this case serves as an emphatic: the verb ανευρισκω (aneurisko), meaning to finally find by having searched diligently (Luke 2:16 and Acts 21:4 only).
• Together with the preposition επι (epi), meaning on or upon: the noun εφευρετης (epheuretes), which is thought to describe an inventor (there are only two known instances of this word in all of Greek literature). In the New Testament, this word is used in Romans 1:30 only, in a context that is often enthusiastically interpreted as referring to premeditated vileness, but that's not necessarily accurate. The associated verb εφευρισκω (epheurisko) means to find out (a secret), to invent (some device or technique), to scheme (to hatch some plan or organize some business venture) or to discover something in addition to something previously discovered. In our modern age, inventors are much appreciated because most moderns respect science and engineering protocols. But in times when inventions were backed merely by the best intentions and the blessings of some distant deity, inventions were prone to produce damage rather than anything else. In societies where good manners and orthodoxy governed the communal peace, novelties were regarded with due suspicion as the seeds of rebellion and corruption of youths (as implied in Acts 17:21). But a "bad inventor" as Paul calls them, is simply someone whose concoctions cause damage and hurt; either indeed someone violent or someone who constructs a piece of technology without knowing anything about engineering, and so builds a house that collapses under the weight of its occupants (or by imprisoning somebody stronger than the house: Judges 16:30), a tower that falls over from poor design, the lack of a proper foundation or maintenance (Luke 13:4) or from poor financial planning (Luke 14:28), or an oven that kills its operators (Daniel 3:22), and so on.