tranquillize vs lull

tranquillize is not a noun while lull is a noun.

Word	Noun	Adjective	Verb	Adverb
tranquillize	No	No	Yes	No
lull	Yes	No	Yes	No

As verbs, tranquillize and lull are synonyms defined as:

Other synonyms of tranquillize include calm, calm down, quiet, quieten, still, tranquilize, tranquillise.

As verbs, lull is a hyponym of tranquillize; that is, lull is a word with a more specific, narrower meaning than tranquillize:

Other hyponyms of tranquillize include compose, appease, assuage, conciliate, gentle, gruntle, lenify, mollify, pacify, placate.

tranquillize (noun)	lull (noun)
	a period of calm weather
	a pause during which things are calm or activities are diminished

tranquillize (verb)	lull (verb)
cause to be calm or quiet as by administering a sedative to	become quiet or less intensive
make calm or still	make calm or still
	calm by deception