a very small insect that is harmful to plants. There are several types of aphid, including, for example, greenfly. Topics Insects, worms, etc.c2蚜虫 Word Originlate 19th cent.: back-formation from aphides, plural of aphis modern Latin, from Greek, perhaps a misreading of koris ‘bug’ (interpreting the characters κoρ ‘kor’ as αϕ ‘aph’).