Slang / euphamism for 'violent(ly insane)'. Spoken of the character 'Brock Sampson' by the character 'The Monarch' on the cartoon show 'The Venture Bros.'
Without a doubt, The USA has gone sickhouse on Iraq since March 20th, 2003.
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!