welt vs lash

welt and lash both are nouns.

Word	Noun	Adjective	Verb	Adverb
welt	Yes	No	Yes	No
lash	Yes	No	Yes	No

As verbs, welt and lash are synonyms defined as:

Other synonyms of welt include flog, lather, slash, strap, trounce, whip.

welt (noun)	lash (noun)
a raised or strengthened seam	a quick blow delivered with a whip or whiplike object
a raised mark on the skin (as produced by the blow of a whip); characteristic of many allergic reactions	leather strip that forms the flexible part of a whip
	any of the short curved hairs that grow from the edges of the eyelids

welt (verb)	lash (verb)
put a welt on	strike as if by whipping
beat severely with a whip or rod	beat severely with a whip or rod
	bind with a rope, chain, or cord
	lash or flick about sharply