A person who is your friend in real life, as opposed to a facebook friend or myspace friend, who is most likely a complete stranger.
Can also be spelled IRLfriend (IRL being an acronym for In Real Life).
"Hey Jim, my buddy just hit me up to ask if I want to go to his party this Saturday night!"
"Is this 'buddy' another one of your facebook friends?"
"No, man, he's my irlfriend."