The Collaborative International Dictionary of English v.0.48:

Fulmar \Ful"mar\ (f[u^]lm[aum]r), n. [Icel. f[=u]lm[=a]r. See
   foul, and Man a gull.] (Zool.)
   One of several species of sea birds, of the family
   Procellariid[ae], allied to the albatrosses and petrels.
   Among the well-known species are the arctic fulmar
   (Fulmarus glacialis) (called also fulmar petrel,
   malduck, and mollemock), and the giant fulmar (Ossifraga
   gigantea).
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Petrel \Pe"trel\, n. [F. p['e]trel; a dim. of the name Peter, L.
   Petrus, Gr. pe`tros a stone (--John i. 42); -- probably so
   called in allusion to St. Peter's walking on the sea. See
   Petrify.] (Zool.)
   Any one of numerous species of longwinged sea birds belonging
   to the family Procellarid[ae]. The small petrels, or Mother
   Carey's chickens, belong to Oceanites, Oceanodroma,
   Procellaria, and several allied genera.
   [1913 Webster]

   Diving petrel, any bird of the genus Pelecanoides. They
      chiefly inhabit the southern hemisphere.

   Fulmar petrel, Giant petrel. See Fulmar.

   Pintado petrel, the Cape pigeon. See under Cape.

   Pintado petrel, any one of several small petrels,
      especially Procellaria pelagica, or Mother Carey's
      chicken, common on both sides of the Atlantic.
      [1913 Webster]

WordNet (r) 3.0 (2006):

fulmar petrel
    n 1: heavy short-tailed oceanic bird of polar regions [syn:
         fulmar, fulmar petrel, Fulmarus glacialis]