slang An involuntary erection that a man achieves during sleep and retains upon awakening. An allusion to the involuntary erection pushing the bedsheets upward into a "tent." I rolled over to snuggle my boyfriend, only to bump off of his morning tent. I hate waking up with both a morning tent and an urgent need to pee!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.