Stands for "All By My Lonesome", and is a reply that someone gives when asked whether he has others with him at a certain time, but he in fact "going solo" on that occasion.
Girl, unexpectedly showing up at a dude's front door: Am I interrupting anything? Do you have others here whom I'd be disturbing?
Guy: Nope, not at all, Sweet Cheex --- I'm a.b.m.l. at da moment. Come right on in and stay a while.
Guy: Nope, not at all, Sweet Cheex --- I'm a.b.m.l. at da moment. Come right on in and stay a while.
by QuacksO December 30, 2018