The Collaborative International Dictionary of English v.0.48:

Crewelwork \Crew"el*work`\ (-w?rk`), n.
   Embroidery in crewels, commonly done upon some plain
   material, such as linen.
   [1913 Webster]

WordNet (r) 3.0 (2006):

crewelwork
    n 1: embroidery done with loosely twisted worsted yarn