The homeless child gave passersby a pathetic look with his sad eyes.

pathetic 来自希腊语 pathos（痛苦、情感），加上形容词后缀 -etic 构成，原意是"能引起同情的"。在现代英语中常表示"可怜的、令人同情的"，有时也带有"可悲的"负面含义。