detain vs decelerate

detain and decelerate both are verbs.

Word	Noun	Adjective	Verb	Adverb
detain	No	No	Yes	No
decelerate	No	No	Yes	No

As verbs, decelerate is a hypernym of detain; that is, decelerate is a word with a broader meaning than detain:

Other hypernyms of detain include retard, slow, slow down, slow up.

detain (verb)	decelerate (verb)
cause to be slowed down or delayed	lose velocity; move more slowly
stop or halt	reduce the speed of
deprive of freedom; take into confinement