Abbott-Smith Manual Greek Lexicon
ἀδάπανος (G77)
1 * ἀδάπανος , -ον ( δαπάνη ), without expense , free of charge : I Co 9:18 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain
Strong's G77 · Greek
ἀδάπανος
adapanos · ad-ap'-an-os
from 1 (as negative particle); and 1160; costless, i.e. gratuitous