bell pepper vs sweet pepper plant

bell pepper and sweet pepper plant both are nouns.

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

As nouns, bell pepper and sweet pepper plant are synonyms defined as:

bell pepper and sweet pepper plant: plant bearing large mild thick-walled usually bell-shaped fruits; the principal salad peppers

Other synonyms of bell pepper include Capsicum annuum grossum, paprika, pimento, pimiento, sweet pepper.

bell pepper (noun)	sweet pepper plant (noun)
large bell-shaped sweet pepper in green or red or yellow or orange or black varieties	plant bearing large mild thick-walled usually bell-shaped fruits; the principal salad peppers
plant bearing large mild thick-walled usually bell-shaped fruits; the principal salad peppers