Acronym for "Let's make it happen", which means what you think it means. However, it usually does not happen. Commonly used in Silicon Valley by overly energetic and undersexed young professionals.
Even though Daniel's friends were all hungover and tired, he wanted to go clubbing in the Castro district, so he kept shouting, "LMIH LMIH LMIH!"
by Dershung April 05, 2010