pepper vs sweet pepper

pepper and sweet pepper both are nouns.

Word	Noun	Adjective	Verb	Adverb
pepper	Yes	No	Yes	No
sweet pepper	Yes	No	No	No

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

pepper: sweet and hot varieties of fruits of plants of the genus Capsicum
sweet pepper: large mild crisp thick-walled capsicum peppers usually bell-shaped or somewhat oblong; commonly used in salads

Other hyponyms of pepper include hot pepper.

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

pepper: any of various tropical plants of the genus Capsicum bearing peppers
sweet pepper: plant bearing large mild thick-walled usually bell-shaped fruits; the principal salad peppers

pepper (noun)	sweet pepper (noun)
pungent seasoning from the berry of the common pepper plant of East India; use whole or ground	large mild crisp thick-walled capsicum peppers usually bell-shaped or somewhat oblong; commonly used in salads
sweet and hot varieties of fruits of plants of the genus Capsicum	plant bearing large mild thick-walled usually bell-shaped fruits; the principal salad peppers
any of various tropical plants of the genus Capsicum bearing peppers
climber having dark red berries (peppercorns) when fully ripe; southern India and Sri Lanka; naturalized in northern Burma and Assam

pepper (verb)	sweet pepper (verb)
attack and bombard with or as if with missiles
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