Green’s Dictionary of Slang

1. (US) an excl. of disgust.

1967		B. Cleary Mitch and Amy 12: ‘Be quiet, both of you,’ said Mrs. Huff, ‘or I shall serve hot oatmeal every morning.’ [...] ‘Oatmeal, ick,’ said Amy.
1972		Nova Apr. 95: ‘Ick,’ Nelson says.
1987		G.A. Fine With the Boys 167: Ish is the Minnesota equivalent of ick or yeech [...] – mild disgust.
2003		Esselman & Velez Kiss Off 156: Yuck, ick, disgusting, is all she can think at first.
2012		L. Berney Whiplash River [ebook] Ick, Gina thought. You’d need a shower after showering with that kind of girl.

2. attrib. use of sense 1.

2004

A. Antliff Only a beginning 183: There is an ‘ick’ factor of absolute disgust.