perk vs pourboire

perk and pourboire both are nouns.

Word	Noun	Adjective	Verb	Adverb
perk	Yes	No	Yes	No
pourboire	Yes	No	No	No

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

perk: an incidental benefit awarded for certain types of employment (especially if it is regarded as a right)
pourboire: a relatively small amount of money given for services rendered (as by a waiter)

Other hyponyms of perk include apanage, appanage, backsheesh, baksheesh, bakshis, bakshish, gratuity, tip.

perk (noun)	pourboire (noun)
an incidental benefit awarded for certain types of employment (especially if it is regarded as a right)	a relatively small amount of money given for services rendered (as by a waiter)

perk (verb)	pourboire (verb)
gain or regain energy