- The material, as cloth, felt, etc., from which a jacket is made.
- A jacket; a cover or protection to an inanimate object, as the felt covering of a steam-pipe.
- A thrashing.
- Surrounding or protecting as a jacket: in <em>physical</em>, said of a layer of insulating material surrounding a calorimeter or other chamber to prevent the inflow or egress of heat.
- The material of a jacket.
- Present participle of <xref>jacket</xref>.