yarn vs weft

yarn and weft both are nouns.

Word	Noun	Adjective	Verb	Adverb
yarn	Yes	No	Yes	No
weft	Yes	No	No	No

As nouns, weft is a hyponym of yarn; that is, weft is a word with a more specific, narrower meaning than yarn:

yarn: a fine cord of twisted fibers (of cotton or silk or wool or nylon etc.) used in sewing and weaving
weft: the yarn woven across the warp yarn in weaving

yarn (noun)	weft (noun)
a fine cord of twisted fibers (of cotton or silk or wool or nylon etc.) used in sewing and weaving	the yarn woven across the warp yarn in weaving
the act of giving an account describing incidents or a course of events

yarn (verb)	weft (verb)
tell or spin a yarn