weld vs butt-weld

weld and butt-weld both are nouns.

Word	Noun	Adjective	Verb	Adverb
weld	Yes	No	Yes	No
butt-weld	Yes	No	Yes	No

As verbs, butt-weld is a hyponym of weld; that is, butt-weld is a word with a more specific, narrower meaning than weld:

Other hyponyms of weld include spot-weld, spotweld, buttweld.

weld (noun)	butt-weld (noun)
a metal joint formed by softening with heat and fusing or hammering together	a butt joint that is welded
European mignonette cultivated as a source of yellow dye; naturalized in North America

weld (verb)	butt-weld (verb)
unite closely or intimately	join by a butt weld
join together by heating