air jacket

from WordNet (r) 3.0 (2006)

air jacket
    n 1: an inflatable life jacket [syn: {Mae West}, {air jacket}]

from The Collaborative International Dictionary of English v.0.48

Air jacket \Air" jack`et\
   A jacket having air-tight cells, or cavities which can be
   filled with air, to render persons buoyant in swimming.
   [1913 Webster]