Also flaunch, FLANGE v. [Of obscure origin; there would seem to be some connection with the synonymous FLAN v.; but the relation between the two words is not explained by any known process of derivation. Assuming the primary sense to be ‘to extend laterally,’ flanch might conceivably be derived from F. flanc FLANK; but no vb. *flancher of similar sense has been discovered in Fr. of any period.
An OF. flanchir, flangir, flainchir occurs as a synonym (perh. a variant) of flechir to bend (cf. FLINCH). Can the Eng. vb. be an adoption of this in a specialized sense?]
intr. To spread, widen out; to slope outwards towards the top. Also with out, off.
1776. Withering, Brit. Plants (1796), IV. 357. Brown on the outside; dark grey and smooth within; the border flanching out.
1802. Trans. Soc. Enc. Arts, XX. 288. The sides, from the floor-heads to the top of the gunwale, flaunch off on each side.
Hence Flanching vbl. sb. and ppl. a.
1802. Gentl. Mag., LXXII. April, 325/1. The boat is about 30 feet long over all, and 10 feet broad, built in a flaunching manner.
1802. Capt. Reed, in Naval Chron., VII. 490. The curvature of the keel and the flaunching sides, which rendered it almost impossible to be upset. Ibid. (1803), IX. 283. The flaunching, or spreading form of the boat, from the floor-heads to the gunwale, gives her a considerable bearing.
