horny

Definitions

Medical

  • adjective referring to skin which is very hard

Slang

  • adjective sexually aroused, lustful. Although the horn in question is the penis (in an image which dates from the 18th century, if not earlier), the expression is now used by and about both sexes, sometimes in colourful phrases such as ‘horny as a hoot-owl’. It is a 1960s successor of longer phrases such as to get the horn, to be on the horn, etc.
http://www.dictionarycentral.com/definition/horny.html