이그 is an interjection expressing a dislike or disapproval on something.
There are many such phrases of interjection:
- 에그, 에이그: similar to 이그, lighter in tone. (에그, 손이 흙투성이네 [to a child] - Gee, your hands are covered with dirt).
- 아이고, 아이구: exclamation of a surprise, worry, of being in pain or fatigue, etc. (아이고, 힘들다 - Ah, I'm beat).
- 에고, 에구, 애고: similar to 아이고/아이구, but maybe slightly lighter in tone.
- 아야: ouch! (reaction to a sharp pain).
- 아이쿠: Similar to 아야, but a little lighter, and more masculine.