A person who is happy or laughs for no reason.
A person who laughs very loudly and annoys everybody.

Shit happy is a transliteration of a tamil phrase: "mayir santhosham"
Ben: Hi Greg. What's up? How was your day?
Greg: HAHAHAHAHAHAHAHA
Ben: Why are you so shit happy?
by Sunny Beach July 1, 2013
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A guy I used to work with told me that he was going take a "happy shit". I asked, " what's that"? And he replied, that's when you are getting paid to shit.
by scottyd62 March 17, 2016
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When something happens in your life that's so bad its like getting a fresh delicious Happy Meal when you're starving to death opening the bag and seeing a big wad of shit on top!
Falling down the up escalator was a Shit in my Happy Meal
by Dr. Schlaktus April 7, 2009
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