1) Acronym for "FUCK MY ASS OFF".

2) A combination of the popular internet phrases "FML" and "LMAO" which can be used in a variety of contexts.

3) An expression of frustration.

4) An expression used to describe sexual activities.
"FMAO, girl! I got blackout and backed into your brother's friend's car last night! FMAO!"

"I tried to have a friendly BBQ and it turned into a goddamned shit show. FMAO!"

"I FMAO'd last night... LIKE A BOSS!"
by Maria & Dan June 21, 2009
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Although it is an abbreviation that stands for "freezing my ass off," FMAO can stand for many things, such as "farting my ass off."
Holy Shit! I should have worn a coat today, I am FMAO!
by fabcookie96 December 5, 2009
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Used to abbreviate Freezing My Arse Off - originates from the infamous LMAO (Laughing My Arse Off) but is used when one is cold.
First used on myspace.com
John: "It's serioulsy cold today!"
Dan: "Too right - I'm fmao here!!"
by James Cartman April 29, 2007
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Abbreviation used to define; "Fucking My Ass Off", less offessively. Commonly mistaken for "Freezing my Ass Off" but this definition should only be used for instances of extreme cold or icy discomfort. People have also discovered that in times of extreme cold and discomfort that proper use of the abbreviation also seems to heat things up a bit.
Andrea: "I'm going to FMAO this weekend!"
Brian: "I am so going to FMAO with her!"
by Lets Get Dirty January 16, 2009
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