Pronunciation:

Gee as in geese
Diu as in the cantonese word for f*ck

1) Adj: Synomymous to "mic", ridiculous, f*cked up, retarded, obnoxious, gross, inconsiderate, sneaky...... any words that gives a condescending meaning to describe a person.

2) Used as an exclamation.

Related words:

Geediu Jing - A person who pocesses the above qualities listed in 1).

Geelunndiu - See 2), but sometimes broken down into gee- and -diu and put "lunn" in between to add emphasis:

3. Geelunndiu~~~~~~~~~~~~~~ !?!?!?!?!?!?!?!?!?!