caster vs shaker

caster and shaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
caster	Yes	No	No	No
shaker	Yes	No	No	No

As nouns, shaker is a hypernym of caster; that is, shaker is a word with a broader meaning than caster:

caster (noun)	shaker (noun)
a pivoting roller attached to the bottom of furniture or trucks or portable machines to make them movable	a container in which something can be shaken
a shaker with a perforated top for sprinkling powdered sugar	a person who wields power and influence
a worker who casts molten metal into finished products