pocket calculator vs calculator

pocket calculator and calculator both are nouns.

Word	Noun	Adjective	Verb	Adverb
pocket calculator	Yes	No	No	No
calculator	Yes	No	No	No

As nouns, calculator is a hypernym of pocket calculator; that is, calculator is a word with a broader meaning than pocket calculator:

pocket calculator: a calculator small enough to hold in the hand or carry in a pocket
calculator: a small machine that is used for mathematical calculations; can be mechanical or electronic

Other hypernyms of pocket calculator include calculating machine.

pocket calculator (noun)	calculator (noun)
a calculator small enough to hold in the hand or carry in a pocket	a small machine that is used for mathematical calculations; can be mechanical or electronic
	an expert at calculation (or at operating calculating machines)