brass monkey vs pedestal

brass monkey and pedestal both are nouns.

Word	Noun	Adjective	Verb	Adverb
brass monkey	Yes	No	No	No
pedestal	Yes	No	No	No

As nouns, pedestal is a hypernym of brass monkey; that is, pedestal is a word with a broader meaning than brass monkey:

brass monkey: a metal stand that formerly held cannon balls on sailing ships
pedestal: a support or foundation

Other hypernyms of brass monkey include base, stand.

brass monkey (noun)	pedestal (noun)
a metal stand that formerly held cannon balls on sailing ships	a support or foundation
	an architectural support or base (as for a column or statue)
	a position of great esteem (and supposed superiority)