Abarim Publications' online Biblical Greek Dictionary
The noun βασανος (basanos) describes a touchstone: a stone upon which a rubbed gold object leaves a recognizable residue that proves its genuineness. This process obviously damages the object, and a better way was developed by Archimedes (who, when he figured it out, famously yelled: Eureka!). Note that this stone would be brought in when some merchant didn't trust the seller, and elected to subject the merchandize to a damaging test rather than risk being duped. This says more about the buyer than about the seller, or the merchandize.
Figuratively, this noun came to denote any sort of test or trial — verification, authentication, audits, KYC, forms and certificates, stamps and seals, passwords and key phrases — by suspicious overlords, and because of the damaging, invasive, degrading and generally terroristic nature of such tests, it ultimately became figurative of torture, instruments of torture, or even torment by disease. It's used in Matthew 4:24, Luke 16:23 and 16:28 only, and particularly since this word describes conditions in Hades, it's prudent to note this word's element of trial, which indicates both intent and suspicion on behalf of the one who's doing the testing, or the accuser in whose name he tests. Our noun stems from an Egyptian word that simply means hard stone. A modern equivalent would be an acid test. From it come:
- The verb βασανιζω (basanizo), originally meaning to put to the test, but eventually taking on the meaning of to torture or torment. Still, our verb emphasizes the element of test and trial, rather than mere punishment, which indicates that the one who torments wants something, or wants to extract something, from the one who is tortured. This is rather insightful, since this verb is often used to describe a suffering from tortuous diseases, and indicates that the ancients were aware of pathogens that ravish the body for their own gain (see the noun βασανιστης, basanistes, below). This verb is used 12 times, see full concordance, and from it in turn come:
- The noun βασανισμος (basanismos), meaning a putting to the test, a torture, a torment. This noun is used 6 times; see full concordance.
- The noun βασανιστης (basanistes), meaning a tester, a torturer, a tormenter. This word occurs in Matthew 18:34 only, where a man is handed over to the tormenter until he paid off all this debts. In this case, the victim was probably not physically tortured, but rather financially, and his tormenter was rather an accountant who dissected his victim's life in search of any remaining properties to sell.