The term photobombing has been in circulation for the past three years or so, and though yet to make it into a mainstream dictionary, is widely used in popular Internet culture and the media. As well as the related noun photobomber for describing those who jump uninvited into the viewfinder, there’s also the word photobomb, which can be used either as a transitive verb (often realized as participle adjective photobombed) or as a countable noun referring to the photo itself.