Pronounced as Thon- (sounds like Loan) -daan (pronounced darn) i.e Thon-daan Ge (pronounced Gay).
Literal Meaning: Take it (my penis) in your mouth. Or Suck my penis. not necessarily for my pleasure but as a demeaning task
Origins: Goan Konkani.
This phrase is used as a means to tell someone off, especially if someone is showing off.
1. I do not believe you, Thondaan Ge.
2. Do not bug me you asshole, Thondaan Ge.
The idea is similar to telling someone to get lost.
This is not about asking someone to give you a blowjob.