Webster's Revised Unabridged Dictionary · 1913

Nab

Nab (nab) , noun

[Compare Knap, Knop, Knob.]

1.
The summit of an eminence. [Provincial English] — Halliwell
2.
(Firearms) The cock of a gunlock. — Knight
3.
(Locksmithing) The keeper, or box into which the lock is shot. — Knight

Nab (nabd) , transitive verb

[Dan nappe, or Swedish nappa.]

1.
To catch or seize suddenly or unexpectedly. [Colloquial] — Smollett
2.
To capture; to arrest; as, the police nabbed the culprit trying to hide in the basement.