The Collaborative International Dictionary of English v.0.48:

Cosier \Co"sier\ (k?"zh?r), n. [Cf. OF. coussier maker of
   mattresses; or couseor tailor, fr. OF. & F. coudre, p. p.
   cousu to sew, fr. L. consuere to sew together; con- + seure
   to sew. See Sew to stitch.]
   A tailor who botches his work. [Obs.] --Shak.
   [1913 Webster]