bootlicker vs lackey

bootlicker and lackey both are nouns.

Word	Noun	Adjective	Verb	Adverb
bootlicker	Yes	No	No	No
lackey	Yes	No	No	No

As nouns, lackey is a hypernym of bootlicker; that is, lackey is a word with a broader meaning than bootlicker:

bootlicker: someone who humbles himself as a sign of respect; who behaves as if he had no self-respect
lackey: a person who tries to please someone in order to gain a personal advantage

Other hypernyms of bootlicker include ass-kisser, crawler, sycophant, toady.

bootlicker (noun)	lackey (noun)
someone who humbles himself as a sign of respect; who behaves as if he had no self-respect	a male servant (especially a footman)
	a person who tries to please someone in order to gain a personal advantage