litchi vs litchee

litchi and litchee both are nouns.

Word	Noun	Adjective	Verb	Adverb
litchi	Yes	No	No	No
litchee	Yes	No	No	No

As nouns, litchi and litchee are synonyms defined as:

litchi and litchee: Chinese fruit having a thin brittle shell enclosing a sweet jellylike pulp and a single seed; often dried

Other synonyms of litchi include leechee, lichee, lichi, litchi nut, lychee.

litchi (noun)	litchee (noun)
Chinese fruit having a thin brittle shell enclosing a sweet jellylike pulp and a single seed; often dried	Chinese fruit having a thin brittle shell enclosing a sweet jellylike pulp and a single seed; often dried
Chinese tree cultivated especially in Philippines and India for its edible fruit; sometimes placed in genus Nephelium