Quick Definition
I under-gird
Strong's Definition
to gird under, i.e. frap (a vessel with cables across the keel, sides and deck)
Derivation: from G5259 (ὑπό) and G2224 (ζώννυμι);
KJV Usage: undergirt
Thayer's Greek Lexicon
ὑποζώννυμι; from Herodotus down; to under-gird: τό πλοῖον to bind a ship together laterally with ὑποζωματα (Plato, de rep. 10, p. 616 c.), i. e. with girths or cables, to enable it to survive the force of waves and tempest, Act_27:17 (where see Overbeck (or Hackett; especially Smith, Voyage and Shipwreck, etc., pp. 107ff, 204ff. (cf. βοήθεια))). (Polybius 27, 3, 3.)
Mounce Concise Greek Dictionary
ὑποζώννυμι hypozōnnymi 1x
to gird under, of persons; to undergird a ship with cables, chains, etc., Act_27:17
Abbott-Smith Greek Lexicon
**ὑπο -ζώννυμι ,
[in LXX : 2Ma_3:19 * ;]
to undergird ( Hdt ., al. ; ὑπὸ τ . μάστους , 2Mac, l.c .); of a ship, to undergird or frap : Act_27:17 ( v. DB , ext. 367a).†
Moulton & Milligan — Vocabulary of the Greek NT
ὑποζώννυμι [page 657]
undergird, frap a ship ( Act_27:17 ) : see Hastings DB v. p. 367. For the subst. ὑποζώνη , a girdle, cf. BGU III. 717 .10 (A.D. 149) (see Berichtigungen , p. 4) ὑποζώνην̣ ὀναγρί (νην ) μίαν , ib. 816 .24 (iii/A.D.) ζεῦγος ὑποζωνῶν , and for the form ὑπόζωνον , not in LS 8 , P Hamb I. 10 .25 (ii/A.D.) ζμαράγδινον ὑπόζωνον καὶ πάλλιον . Ὑπόζωμα is found in Syll 537 ( = .3 969) .74 (B.C. 347 6) μεσόμνας ( shafts ), ἐφ᾽ ὧν κείσεται τὰ ὑποζώματα καὶ τἆλλα σκεύη : see Dittenberger s note.
Liddell-Scott — Intermediate Greek Lexicon
ὑποζώννυμι and -ύω fut. -ζώσω Pass., perf. ὑπ-έζωσμαι "to undergird", Plut. :—Pass., ζειρὰς ὑπεζωσμένοι "girt" with ζειραί, Hdt. "to undergird or frap" a ship (v. ὑπόζωμα II), Polyb. , NTest.
STEPBible — Tyndale Abridged Greek Lexicon
ὑπο-ζώννυμι
[in LXX: 2Ma.3:19 * ;]
to undergird (Hdt., al.; ὑπὸ τ. μάστους, 2Mac, l.with); of a ship, to undergird or frap: Act.27:17 (see DB, ext. 367a).†
(AS)