Source : Webster's Revised Unabridged Dictionary (1913)

Opinionated \O*pin"ion*a`ted\, a.
   Stiff in opinion; firmly or unduly adhering to one's own
   opinion or to preconceived notions; obstinate in opinion.
   --Sir W. Scott.

Source : WordNet®

opinionated
     adj : obstinate in your opinions [syn: {opinionative}, {self-opinionated}]