photobomb 

(verb)- to drop in a photo unexpectedly...to hop in a picture right before it is taken.

sarah: hey why is jimmy in the background of our prom picture?
ryan: idk, he must have photobombed it at the last second.

photobomb by jervis_star1 June 27, 2008

Photobomb 

An otherwise normal photo that has been ruined or spoiled by someone who was not supposed to be in the photograph.

The most common photobomb is someone in the background making a face.

Photobomb by Teresa from OK November 16, 2009

photobomb 

Any time the background of a picture hijacks the original focus.

Uncle Bob's hairy ass totally photobombed that picture.

photobomb by photobomber May 9, 2009

Photobomb 

The one innocent thing you should NEVER say at an airport.

Guy: "Photobomb!"
*CLICK*
(Get booted off the flight)

Photobomb by Sherlock21st May 9, 2011

Photobomb 

to jump in a picture right before it is taken in Ontario, Canada it is known as the pop-in

im gonna photobomb all your nice pictures

i gotta go try and rock some pop-ins

Photobomb by CHUBBYdaking March 29, 2010

photobomb 

the explosion of tagged pictures from multiple sources to a person's facebook page after an event.

when i got back from mexico my facebook page was photobombed.

photobomb by rmashate November 2, 2009

Reverse Photobomb 

(verb)- a photo taken without the knowledge and awareness of the person in the foreground, but known and planned by the person in the background and the photo taker. Basically the reverse of a traditional photobomb, where someone unsuspectingly jumps into the background of a people-posed photo.

Lark: Hey Jan, let's reverse photobomb Craig!
Jan: I'll run up behind Craig and pose. If he see's me, he'll have no idea what I'm doing.
Lark: This is going to be a great RPB pic! Let's RPB Gike Mallego next!

Reverse Photobomb by Captain Incredible x Infinity June 2, 2015