English

Adjective

1. Encased or enclosed inside a jacket.
   • 1861: United States War Dept, Annual Reports

     One of the advantages of a matrix would be to reduce the cost of our shrapnel by enabling hardened lead balls and round cases to be used in place of the steel-jacketed balls and hexagonal cases...

   • 1920: Edward J. Martin, The Traffic Library: Principles of Classification

     The metal can completely jacketed must have iron, steel or wooden jacket completely covering the can, except the mouth.

Verb

1. past of jacket