Interjection (derived from past participle of GrOwn).
Abbreviation for "Grammar Owned," a phrase adapted from the now popular term "Owned," which denotes the dominance of the listening (owned) person by the speaking person.
The interjection is triggered by some event which demonstrates one person's
inferiority to another.
In this case, it refers to the
grammatical superiority of the GrOwner, and is in response to a
grammatical error committed by the GrOwned person.
Alternate spellings: Grpwned, Grpwn3d, GrOwn3d, Gr0wned, Gr0wn3d, Groaned.