The Collaborative International Dictionary of English v.0.48:

Cocket \Cock"et\, a. [F. coquet coquettish. See Coquette, n.]
   Pert; saucy. [Obs.] --Halliwell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cocket \Cock"et\, n.
   1. (Eng. Law) A customhouse seal; a certified document given
      to a shipper as a warrant that his goods have been duly
      entered and have paid duty.
      [1913 Webster]

   2. An office in a customhouse where goods intended for export
      are entered. [Eng.]
      [1913 Webster]

   3. A measure for bread. [Obs.] --Blount.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

COCKET, commerce. In England the office at the custom house, where the goods
to be exported are entered, is so called, also the custom house seal, or the
parchment sealed and delivered by the officers of customs to merchants, as a
warrant that their goods are customed. Crabbe's Tech. Dict.