The Collaborative International Dictionary of English v.0.48:

Burnet \Bur"net\, n. [OE. burnet burnet; also, brownish (the
   plant perh. being named from its color), fr. F. brunet, dim.
   of brun brown; cf. OF. brunete a sort of flower. See
   Brunette.] (Bot.)
   A genus of perennial herbs (Poterium); especially,
   Poterium Sanguisorba, the common, or garden, burnet.
   [1913 Webster]

   Burnet moth (Zool.), in England, a handsome moth
      (Zyg[ae]na filipendula), with crimson spots on the
      wings.

   Burnet saxifrage. (Bot.) See Saxifrage.

   Canadian burnet, a marsh plant (Poterium Canadensis).

   Great burnet, Wild burnet, Poterium oficinalis (or
      Sanguisorba oficinalis).
      [1913 Webster]