Best definition
A Chinese person, living in an English speaking country, that has little-to-no understanding of the language, slang and general day-to-day

concepts of that country.
Comes from the likelihood that the person will often ask Whassah? (what’s that) in relation to any word, concept or social practice that seems alien to them!
Whassahs also do many things in everyday life that make them seem thouroughly weird to anyone that spends much time with them, such as cooking eggs in pots of tea and making food that even pigs would refuse.

That student accomodation has so many goddamn Whassahs living in it. There’s no way i’m staying there again!