the elm is an unfruitful

ἄκαρπος, ον (Aeschyl. et al.; ins, pap, LXX; TestNaphth 3:5; ParJer 9:16; Jos., Ant. 2, 213; 15, 300; Just., D. 120, 2)

① lit. pert. to not bearing fruit, unfruitful, fruitless. πτελέα ξύλον ἄ. the elm is an unfruitful (i.e. bearing no edible fruit, s. Pollux I 234) tree Hs 2:3. δένδρα ἄ. (Theophyl. Sim., Ep. 11) unfruitful trees (w. φθινοπωρινά) as a type of dissident teachers Jd 12, cp. Hs 4:4. Of a mountain, on which nothing grows (Jos., Bell. 4, 452) ὄρος ἄ. unfruitful, barren Hs 9, 19, 2.

② fig. pert. to being useless, useless, unproductive (IPriene 112, 16; Jos., Bell. 6, 36) of seed (preaching) Mt 13:22; Mk 4:19 (Pla., Phdr. 277a λόγοι ἄ; Synes., Dion 3 p. 39c λόγος ἄ.). Of deeds ἔργα ἄ. τοῦ σκότους useless deeds of darkness Eph 5:11. Of people who do no good deeds (Philostrat., Gymn. 42 p. 284, 11) Tit 3:14; 2 Pt 1:8 (cp. OdeSol 11:23). Of speaking in tongues νοῦς ἄ. ἐστιν (my) mind is unproductive, because it is not active 1 Cor 14:14.—DELG s.v. 1. καρπός. M-M. TW. Spicq.