Quick Definition
falling headlong
Strong's Definition
leaning (falling) forward ("prone"), i.e. head foremost
Derivation: from G4253 (πρό);
KJV Usage: headlong
Thayer's Greek Lexicon
πρηνής, πρηνες (allied with πρό; Vanicek, p. 484), Latinpronus, headlong: Act_1:18. (Wis_4:19; 3Ma_5:43; in Greek writings from Homer down, but in Attic more common πρανής, see Lob. ad Phryn., p. 431; (Winer's Grammar, 22).)
Mounce Concise Greek Dictionary
πρηνής prēnēs 1x
prone, head-foremost; πρηνὴς γενόμενος , falling head-long, Act_1:18
Abbott-Smith Greek Lexicon
** πρηνής , -ές
(in Att. . also πρανής ),
[in LXX : Wis_4:19 , 3Ma_5:43 ; 3Ma_5:50 ; 3Ma_6:23 * ;]
headlong , prone: Act_1:18 .†
Moulton & Milligan — Vocabulary of the Greek NT
πρηνής [page 535]
an Ionic form for Attic πρανής (cf. Moulton Gr. ii. p. 68), found in the NT only in Act_1:18 πρηνὴς γενόμενος . As against the AV and RV falling headlong (supported by Boisacq s derivation from πρό , p. 812), Chase ( JTS xiii. (1912) p. 278 ff.) shows good reasons for taking πρηνής as a medical term = swollen up (cf. Sap 4:19) : see further Harnack ThLZ xxxvii. (1912), p. 235. If so, the root is pr̯ , burn : cf. Rendel Harris s suggestion ( AJT iv. (1900), p. 490 ff.) that for πρηνὴς γενόμενος we should read πρησθείς . A.D. Knox ( JTS xxv. (1924), p. 289 f.) prefers to transpose πρηνής and μέσος , and to translate when he arrived in the midst of it he fell headlong.
Liddell-Scott — Intermediate Greek Lexicon
πρηνής πρηνής, ές [Etym: πρό] "with the face downwards, head-foremost", Lat. pronus, opp. to ὕπτιος (Lat. supinus), Il. , Hes. of the sides of hills, πρὸς κατὰ πρανοῦς "down hill", Xen. ; κατὰ τὰ πρανῆ id=Xen.
STEPBible — Tyndale Abridged Greek Lexicon
πρηνής, -ές
(in Att.. also πρανής), [in LXX: Wis.4:19, 3Ma.5:43 3Mac 5:50 3Mac 6:23 * ;]
headlong, prone: Act.1:18.†
(AS)