sleh Share definition Flag When the words "see you later!" is said so quickly you break the sound barrier and a series of words becomes a harmoneous sound. Like a yelp. "I gotta go, if I stay I'll die. sleh!" "I'm probably never gonna see you again. sleh!" sleh by iamdavidprice November 6, 2011 0 0 Get merch Get the sleh mug. Buy Now — $32.95 See more merch