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1.
acronym: Rolling On Floor Laughing, Coughing Up Phlegm

It may be extended to indicate the quantity or duration of ROFLCUP by using ROFLCUPful as a measuring unit.
He had a bad cold and so his mates' Facebook comments made him ROFLCUP.

While ROFL he had a phlegmgasm and hoiked up a ROFLCUPful of lung juice.
by memeweaver July 17, 2012