substantiate vs strengthen

substantiate and strengthen both are verbs.

Word	Noun	Adjective	Verb	Adverb
substantiate	No	No	Yes	No
strengthen	No	No	Yes	No

As verbs, strengthen is a hypernym of substantiate; that is, strengthen is a word with a broader meaning than substantiate:

Other hypernyms of substantiate include beef up, fortify.

substantiate (verb)	strengthen (verb)
solidify, firm, or strengthen	give a healthy elasticity to
establish or strengthen as with new evidence or facts	gain strength
make real or concrete; give reality or substance to	make strong or stronger
represent in bodily form