Webster's Revised Unabridged Dictionary · 1913

Knab

Knab (nab) , transitive verb

[See Nab, transitive verb, and compare Knap, transitive verb]

1.
To seize with the teeth; to gnaw. [Obsolete]
Knabbing crusts. — L'Estrange
2.
To nab. See Nab, transitive verb [Colloquial]