Limfac is a short form for "limiting factor," often used by technicial and military people to describe a device or procedure's weakest or least efficient part. See also achilles heel.
A word the people who make those drug surveys they give us at school made up. They stick in made up words to see if people are just checking yes for every answer. If they check yes for "limjack", they just throw the survey away.
A spoken word derived from the abbreviation for Laughing My Fucking Ass Off (L.M.F.A.O). It can be used in context with the spoken word Roffle. Most often a response when someone says something funny or when "Roffle" is said.
Man: Oh man, that was so funny!
Woman: ROFFLE!
Man: LIMFAO!
Girl: Roffle limfao!