E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Nab.
To seize without warning. A contraction of apprehend. (Norwegian, nappe, to catch at, nap, snatch; Swedish, nappa.) Our nap (to filch or steal) is a variety of the same word.
1
The keeper or catch of a latch or bolt is called the nab.
