To be set upon by invasive action while sitting on the toilet; whether by someone banging on the door, peering through the gap in the door to the sitter's stall, etc. Reference to Jurassic Park scene where Gennaro (film, or Ed Regis in the book), is terrorized, then eaten by a T-Rex.
2. The stall doors are always closed at the airport, so they always look full-up. I T-Rexed 3 guys before I found an empty seat.
3. Will you stop banging on the damn door? Dad already T-Rexed me a minute ago! I'll be done in a minute or two!
Joe: I know, he's T-Rexed; just look at his hands!
Bob: Hahahaha! He's swaying in the wind too!