On top of, In addition to, Not only... but also
This expression indicates that the action or state in the following clause occurs in addition to that stated in the preceding clause. The form -(으)ㄴ/는 데다 can also be used.
1. This expression requires that the subjects of the preceding and following clauses be the same. Moreover, both of the clauses must be related and be able to be connected by 그래서 or 그러니까 to state a conclusion.
2. When used with a noun, 에다가 is used to indicate the adding of a noun in the following clause to that mentioned in the first clause, as if making a list, it can also be used to indicate the location in which something is done or placed.