The Collaborative International Dictionary of English v.0.48:

Groats \Groats\, n. pl. [OE. grot, AS. gr[=a]tan; akin to Icel.
   grautr porridge, and to E. gritt, grout. See Grout.]
   Dried grain, as oats or wheat, hulled and broken or crushed;
   in high milling, cracked fragments of wheat larger than
   grits.
   [1913 Webster]

   Embden groats, crushed oats.
      [1913 Webster]

WordNet (r) 3.0 (2006):

groats
    n 1: the hulled and crushed grain of various cereals