Longman Dictionary of Contemporary English
eggplant
egg·plant /ˈegplɑːnt US -plænt/ n [U and C] AmE
a large vegetable with smooth purple skin
British Equivalent: aubergineLangdao E-C Dictionary
eggplant ['egplɑ:nt]
n. 茄子Oxford Advanced Learner’s Dictionary
eggplant
noun
[C, U] (AmE) = AUBERGINECollins Cobuild Advanced Learner's English Dictionary
eggplant
eggplant eggplants
An eggplant is a vegetable with a smooth, dark purple skin. (AM; in BRIT use aubergine)
上面是字典查到的
是既可以作为可数名词,也可以不可数.但是一般人都当作可数用