The Collaborative International Dictionary of English v.0.48:

Acton \Ac"ton\, n. [OF. aketon, auqueton, F. hoqueton, a quilted
   jacket, fr. Sp. alcoton, algodon, cotton. Cf. Cotton.]
   A stuffed jacket worn under the mail, or (later) a jacket
   plated with mail. [Spelled also hacqueton.] [Obs.]
   --Halliwell. Sir W. Scott.
   [1913 Webster]