'Limb of the law' definitions:

Definition of 'Limb of the law'

From: GCIDE

Limb \Limb\ (l[i^]m), n. [OE. lim, AS. lim; akin to Icel. limr limb, lim branch of a tree, Sw. & Dan. lem limb; cf. also AS. li[eth], OHG. lid, gilid, G. glied, Goth. li[thorn]us. Cf. Lith, Limber.]
1. A part of a tree which extends from the trunk and separates into branches and twigs; a large branch. [1913 Webster]
2. An arm or a leg of a human being; a leg, arm, or wing of an animal. [1913 Webster]
A second Hector for his grim aspect, And large proportion of his strong-knit limbs. --Shak. [1913 Webster]
3. A thing or person regarded as a part or member of, or attachment to, something else. --Shak. [1913 Webster]
That little limb of the devil has cheated the gallows. --Sir W. Scott. [1913 Webster]
4. An elementary piece of the mechanism of a lock. [1913 Webster]
Limb of the law, a lawyer or an officer of the law. [Colloq.] --Landor. [1913 Webster]