그거
geugeo · TOPIK 1
that (thing), it (colloquial)
그거 = 그 (that) + 거 (thing, casual 것)
그 means that, and 거 is the spoken short form of 것 (thing). Together: that thing, or simply it. The formal written version is 그것; everyday speech drops the final ㅅ to give 그거.