A person in a group chat on Facebook messenger who looks at last message sent but ignores or doesn't respond to the message.
Marco is always the only person in the chat that insists on being a peeker. PeekingPeter pufferi3
When you're wearing loose boxers and your penis slides out to the side, next to your thigh.
"Hey man, you finished with the shower? Don't worry, I've got my boxers on"
"Oh Damn. Someone's got a peeker."
When a female can sense people/someone staring at her bum as she walks or leaves a room
“Zac is such a peeker i knew he was staring at my bum when i left the room”
The sensation when you have to poop and the turd is peeking out of your asshole.
I have to find a bathroom quick, I've got a peeker!
Where a strange man comes into your house peeks at your butthole to see if your clean/have wiped thoroughly.
I heard that Hudson Frensley got peeked by the butthole peeker, hopefully he won't peek me!