To descibe something disgusting.
"My mums b/f stole the camera from me cause he didn't want me to see the naked pics of my mum....that's so OMFG YEECH!!"
by Fox April 01, 2004
Greeting used to define extreme shock and astonishment when talking to a friend.
by Fox February 17, 2004
The area between the anus and the vagina/testicles.
If you think my ball sweat is bad, smell my yeech.
by Peter Pants April 22, 2006