Source : Webster's Revised Unabridged Dictionary (1913)

Betelguese \Bet"el*guese\ (b[e^]t"[e^]l*j[=e]z), n. [F.
   B['e]telgeuse, of Arabic origin.] (Astron.)
   A bright star of the first magnitude, near one shoulder of
   Orion. [Written also {Betelgeux} and {Betelgeuse}.]

Source : WordNet®

Betelgeuse
     n : the second brightest star in Orion [syn: {Alpha Orionis}]