pen up

verb

1. To enclose (animals) in a pen.
2. To enclose as if in a pen.

   “Pent up in Utica he vainly forms / A poor Epitome of Roman Greatneſs, / And, cover’d with Numidian Guards, directs / A feeble Army, and an empty Senate, / Remnants of mighty Battels fought in vain.”