Used to describe an individual of non-asian heritage/descent, who is heavily influenced by asian culture, and/or tries to be/act like an asian person.
"Just because I have Hello Kitty stationary, watch Sailor Moon and Dragon Ball Z, am a wizz at Dance Dance Revolution and visit China Town whenever I can doesn't make me a trasian!"
"Yes... yes it does"
You'll find the perfect outfit, no worries. You're a trasian.