booster vs pillar

booster and pillar both are nouns.

Word	Noun	Adjective	Verb	Adverb
booster	Yes	No	No	No
pillar	Yes	No	No	No

As nouns, pillar is a hyponym of booster; that is, pillar is a word with a more specific, narrower meaning than booster:

booster (noun)	pillar (noun)
an additional dose that makes sure the first dose was effective	(architecture) a tall vertical cylindrical structure standing upright and used to support a structure
the first stage of a multistage rocket	a vertical cylindrical structure standing alone and not supporting anything (such as a monument)
an amplifier for restoring the strength of a transmitted signal	a fundamental principle or practice
a thief who steals goods that are in a store	a prominent supporter
someone who is an active supporter and advocate	anything that approximates the shape of a column or tower
a person who backs a politician or a team etc.