Lexical Definition

‎πλεονέκτης‎ pleonéktēs (pleh-on-ek'-tace) greedy ^G:N-M
from ‎πλείων‎ and ‎ἔχω‎

covetous.

• holding (desiring) more, i.e. eager for gain (avaricious, hence a defrauder)

Abbott-Smith

** πλεονέκτης, -ου, ὁ (< πλέον, ἔχω), [in LXX: Si 14:9*;] = ὁ θέλων πλέον ἔχειν (v. MM, xx),
one desirous of having more, covetous: I Co 5:10, 11 6:10, Eph 5:5.†

Abbott-Smith References

Liddell-Scott-Jones

πλεονέκτης-ης, ου, ὁ,

={ὁ πλέον ἔχων}, one who has or claims more than his due, greedy, grasping, [Refs 5th c.BC+] adjective λόγος π. a greedy, arrogant speech, [Refs 5th c.BC+]: superlative πλεονεκτίστατος [Refs 5th c.BC+]

__2 ἐν παντὶ πλεονέκτηςην τῶν πολεμίων making gain from their losses, [Refs]
__3 metaphorically in in Mathematics texts, of τὸ ὑπερτελές, [Refs 4th c.AD+]