Unfortunately, you can't. While "Laugh out loud" or "Laughing out loud" are the most widely used meanings,
AcronumFinder.com says it can also stand for:
Lots of love
Lots of luck
List of links
Little old lady
Loss of life
Language of love
Lack of love
Lowest of low
Laws of life
Learn on-line
Loads of laughs
Lots of lag (on-line gaming)
Life of loan (banking)
Lord oh Lord
Log on later
Land of love
Lips on lips (oooh, I like that one)
Lewd obscene language
Lawyers on-line
Leaning over laughing
Liar of lies
...and about 90 other meanings. I guess it depends upon the context in which it is used. (Or if it comes with a smiley face.)