kam lan pronounced as "come lan"
kam: suck
lan: cock (which lan ciao is full word)
It is a Hokkien(a Chinese dialect) word for cock sucking, literally.
It also means a cocksucker, nonsense, go to hell.
Example
As in cock sucking:
That girl likes to kam lan.
As in cocksucker:
Shit, you can ask him to kam lan
As in go to hell:
I think you better kam lan
39👍 10👎