morale building vs morale booster

morale building and morale booster both are nouns.

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

As nouns, morale building and morale booster are synonyms defined as:

morale building and morale booster: anything that serves to increase morale

Other synonyms of morale building include morale builder.

morale building (noun)	morale booster (noun)
anything that serves to increase morale	anything that serves to increase morale