quieten vs tranquillize

quieten and tranquillize both are verbs.

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

As verbs, quieten and tranquillize are synonyms defined as:

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

quieten (verb)	tranquillize (verb)
cause to be quiet or not talk	cause to be calm or quiet as by administering a sedative to
make calm or still	make calm or still
become quiet or quieter