'To catch a tartar' definitions:

Definition of 'To catch a tartar'

From: GCIDE

Tartar \Tar"tar\, n.
1. [Per. T[=a]t[=a]r, of Tartar origin.] A native or inhabitant of Tartary in Asia; a member of any one of numerous tribes, chiefly Moslem, of Turkish origin, inhabiting the Russian Europe; -- written also, more correctly but less usually, Tatar. [1913 Webster]
2. A person of a keen, irritable temper. [1913 Webster]
To catch a tartar, to lay hold of, or encounter, a person who proves too strong for the assailant. [Colloq.] [1913 Webster]