sissy adj: having uncommon feminine qualities ( i think acting like girls ) noun: a timid man or boy considered childish or unassertive

It's a derogatory term for a gay male, and somewhat archaic at that.

a sissy boy = 兔儿爷 “C货”: 系由英语 "Sissy” 所衍生而来,指气质阴柔的男同志。 夸张 = exaggerate