Abarim Publications' online Biblical Greek Dictionary
The verb ελεγχω (elegcho) means to expose or prove wrong. It stems from a Proto-Indo-European root "hleng-" of unclear meaning (but possibly to revile), and is used in the Classics predominantly with the meaning of to shame or put to shame, either with actual or implied examination, testing, proofs to the contrary, corrections, refutations, and so on.
In the New Testament, this verb is often used with less hostility and the wrong-proving is predominantly done in a spirit of kindness, helpfulness and brotherly love (Revelation 3:19). Still, this verb is never about simply yelling at someone that they're wrong, dumb and obtuse, but rather about calmly submitting evidence that contradicts erroneous convictions — which, in no small part, also depends on the empathic creativity and rhetorical skills of the one who is doing to proving. Contrary to common perception, nobody likes to be wrong about anything, since incorrect beliefs are detrimental to the efficiency of the economy. Proving someone wrong is like healing them from a disease, and if done with love and patience, will certainly result in wholesale happiness, gratitude and ultimately prosperity and peace.
This verb is used 18 times, see full concordance, and from it come:
- The noun ελεγξις (elegxis), which describes an momentary instant of the action of the verb: an exposure, a conviction of being wrong, a wrong-proving (2 Peter 2:16 only).
- The noun ελεγχος (elegchos), which describes the long-term result of the action of the verb: an exposure, a conviction of having been wrong, an altered intellectual position, an amended persuasion (2 Timothy 3:16 and Hebrews 11:1 only). In the latter verse, the author submits his famous definition of faith, which contains the clause "the exposure of the unseen".