perp

noun

1. (slang)A perpetrator.

   “"We have the perp in custody," the policeman said.”

   “Got himself fired for pulling a sword on an acknowledged perp. Slid it right through the fabric of the perp’s shirt, gliding the flat of the blade along the base of his neck, and pinned him to a warped and bubbled expanse of vinyl siding on the wall of the house that the perp was trying to break into.”

2. A perpetual bond.
3. Perpetual futures.

   “Autopsies carried out since then [Oct 2025 crypto crash] suggest that much of the damage can be traced to investors having piled into financial products known as perpetual futures. So-called perps allow traders to make highly leveraged bets, up to 100-to-1 on some crypto exchanges, to boost their returns on market moves.”

adj

1. (abbreviation, alt-of, clipping)Clipping of perpendicular.

   “a perp window”