Origin obscure. Perhaps from snape, a dialectal variant of sneap (“to nip, bite, pinch”). More at sneap.
Meanings
To bevel the end of a timber to fit against an inclined surface.
It had to be accurately cut and trimmed, and its upper edge scored to suit the snaping of every beam end. 2000, William L. Crothers, The American-built Clipper Ship, 1850-1856, International Marine, page 265:
From Middle English snaipen (“to injure; of sleet or snow: to nip; to criticize, rebuke, revile”) [and other forms], from Old Norse sneypa (“to disgrace, dishonour; to outrage”), from Proto-Germanic *snupaną, *snubaną (“to cut; to snap”); further origin unknown. Doublet of sneap.
Meanings
(UK, archaic, dialectal, transitive) To check or curtail (the growth of something); also, to check or curtail the growth of (a plant, etc.).
(UK, archaic, dialectal, transitive) Synonym of sneap (“to check or abruptly reprove (someone); to chide, to rebuke, to reprimand”).
The colnel (sic) I dont think like him much. I undirstand (sic) he was always snaping him. 1861, Terry A. Johnston, Him on One Side and Me on the Other, Univ. of South Carolina Press, p48, 1999 (quoting Alexander Campbell)
(UK, archaic, dialectal, intransitive) To chide, to rebuke, to reprimand.
He saw nothing, heard nothing, rushed on, he knew not whither, snaping, and uttering hoarse cries. 1871, John Esten Cooke, Out of the Foam:
I imagine her prodding my flab and snaping, "There's nothing there — get rid of that!" 2001, Joan Raphael-Leff, Pregnancy: The Inside Story, Karnac Books, page 22: