The Collaborative International Dictionary of English v.0.48:

Cop \Cop\ (k[o^]p), n. [AS. cop; cf. G. kopf head. Cf. Cup,
   Cob.]
   1. The top of a thing; the head; a crest. [Obs.]
      [1913 Webster]

            Cop they used to call
            The tops of many hills.               --Drayton.
      [1913 Webster]

   2. A conical or conical-ended mass of coiled thread, yarn, or
      roving, wound upon a spindle, etc.
      [1913 Webster]

   3. A tube or quill upon which silk is wound.
      [1913 Webster]

   4. (Mil. Arch.) Same as Merlon.
      [1913 Webster]

   5. A policeman. [Slang]
      [1913 Webster]

   Cop waste, a kind of cotton waste, composed chiefly of
      remnants of cops from which the greater part of the yarn
      has been unwound.
      [1913 Webster] copacetic

WordNet (r) 3.0 (2006):

cop
    n 1: uncomplimentary terms for a policeman [syn: bull, cop,
         copper, fuzz, pig]
    v 1: take by theft; "Someone snitched my wallet!" [syn: hook,
         snitch, thieve, cop, knock off, glom]
    2: take into custody; "the police nabbed the suspected
       criminals" [syn: collar, nail, apprehend, arrest,
       pick up, nab, cop]

Moby Thesaurus II by Grady Ward, 1.0:

66 Moby Thesaurus words for "cop":
   Dogberry, John Law, abstract, and, annex, appropriate, bag,
   bluecoat, bobby, boost, borrow, bull, cabbage, clout, complex cone,
   cone, conelet, conoid, copper, cornet, crib, defraud, dick,
   embezzle, extort, filch, flatfoot, flattie, funnel, fuzz, gendarme,
   gumshoe, heat, hook, ice-cream cone, lift, make off with, man, nab,
   nip, officer, palm, peeler, pig, pilfer, pinch, pine cone, poach,
   purloin, run away with, rustle, scrounge, shamus, shoplift, snare,
   snatch, snitch, steal, swindle, swipe, take, the cops, the fuzz,
   the law, thieve, walk off with



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

COP
       Character-Oriented Protocol