Term used to describe yourself if your proficiency in chinese is only conversational as opposed to fluent.
Dim sum refers to chinese brunch and therefore dim sum chinese means one can only speak chinese well enough to make it through an afternoon eating dim sum with fluent chinese speaking family members.
Someone who can only speak dim sum chinese most likely cannot understand most of chinese radio, tv shows or songs.
Very common amongst ABC's (american born chinese)
Hey, I'm kind of nervous about you meeting my parents tomorrow. I feel like they would disapprove of me dating someone who can only speak dim sum chinese.