Translation:A beard under your nose is a moustache.
It's "your" nose, so it should have 너의.
Not really. In English, "your" can be used to describe generalities.
The beard under a nose is a moustache
This doesn't even make sense..
코 (nose) + 수염 (beard) = 콧수염 (nose-beard, AKA moustache) (:
It's a Korean play on words. 수염 is beard, 콧수염 is mustache.