morale building vs boost

morale building and boost both are nouns.

Word	Noun	Adjective	Verb	Adverb
morale building	Yes	No	No	No
boost	Yes	No	Yes	No

As nouns, boost is a hypernym of morale building; that is, boost is a word with a broader meaning than morale building:

Other hypernyms of morale building include encouragement.

morale building (noun)	boost (noun)
anything that serves to increase morale	the act of giving hope or support to someone
	the act of giving a push
	an increase in cost

morale building (verb)	boost (verb)
	increase or raise
	give a boost to; be beneficial to
	push or shove upward, as if from below or behind
	increase
	contribute to the progress or growth of