robe vs garb

robe and garb both are nouns.

Word	Noun	Adjective	Verb	Adverb
robe	Yes	No	Yes	No
garb	Yes	No	Yes	No

As verbs, garb is a hypernym of robe; that is, garb is a word with a broader meaning than robe:

Other hypernyms of robe include apparel, clothe, dress, enclothe, fit out, garment, habilitate, raiment, tog.

robe (noun)	garb (noun)
any loose flowing garment	clothing of a distinctive style or for a particular occasion
outerwear consisting of a long flowing garment used for official or ceremonial occasions

robe (verb)	garb (verb)
clothe formally; especially in ecclesiastical robes	provide with clothes or put clothes on
cover as if with clothing