The literal meaning of a person perched on a roof beam, originating from a story about Chen Shi in the Later Han Dynasty.

陈寔对躲在屋顶的梁上君子说，坏人并非生来就是坏的。

noun · A figurative expression or euphemism for a burglar or thief.

由于主人疏忽大意，昨晚家里招了梁上君子。