Senses
小弟 younger brother
The youngest of one's brothers; can also refer generally to any younger brother.
小弟 [self-address]
A humble way for a male to refer to himself when speaking to peers or friends.
小弟 junior
A friendly or informal way to address a male younger than oneself.
小弟 waiter
A young male attendant or server in the service industry, such as in a restaurant or delivery service.
小弟 underling
A subordinate, lackey, or henchman, typically in a gang or a hierarchy