The Collaborative International Dictionary of English v.0.48:

Grill \Grill\, v. t. [imp. & p. p. Grilled; p. pr. & vb. n.
   Grilling.] [F. griller, fr. gril gridiron, OF. gra["i]l, L.
   craticulum for craticula fine hurdlework, a small gridiron,
   dim. of crates hurdle. See Grate, n.]
   [1913 Webster]
   1. To broil on a grill or gridiron.
      [1913 Webster]

            Boiling of men in caldrons, grilling them on
            gridirons.                            --Marvell.

   2. To torment, as if by broiling. --Dickens.
      [1913 Webster]

   3. To stamp or mark with a grill.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

grilled
    adj 1: cooked by radiant heat (as over a grill) [syn: broiled,
           grilled]
    2: cooked over an outdoor grill [syn: barbecued, grilled]