The Collaborative International Dictionary of English v.0.48:
Chop \Chop\, n. [Chin. & Hind. ch[=a]p stamp, brand.] [1913 Webster] 1. Quality; brand; as, silk of the first chop. [1913 Webster] 2. A permit or clearance. [1913 Webster] Chop dollar, a silver dollar stamped to attest its purity. chop of tea, a number of boxes of the same make and quality of leaf. Chowchow chop. See under Chowchow. Grand chop, a ship's port clearance. --S. W. Williams. [1913 Webster]