fruitlet vs fruit

fruitlet and fruit both are nouns.

Word	Noun	Adjective	Verb	Adverb
fruitlet	Yes	No	No	No
fruit	Yes	No	Yes	No

As nouns, fruit is a hypernym of fruitlet; that is, fruit is a word with a broader meaning than fruitlet:

fruitlet: a diminutive fruit, especially one that is part of a multiple fruit
fruit: the ripened reproductive body of a seed plant

fruitlet (noun)	fruit (noun)
a diminutive fruit, especially one that is part of a multiple fruit	an amount of a product
	the consequence of some effort or action
	the ripened reproductive body of a seed plant

fruitlet (verb)	fruit (verb)
	bear fruit
	cause to bear fruit