The Collaborative International Dictionary of English v.0.48:

Barrister \Bar"ris*ter\, n. [From Bar, n.]
   Counselor at law; a counsel admitted to plead at the bar, and
   undertake the public trial of causes, as distinguished from
   an attorney or solicitor. See Attorney. [Eng.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

barrister
    n 1: a British or Canadian lawyer who speaks in the higher
         courts of law on behalf of either the defense or
         prosecution

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "barrister":
   advocate, agent, amicus curiae, attorney, attorney-at-law,
   barrister-at-law, counsel, counselor, counselor-at-law, deputy,
   friend at court, intercessor, lawyer, legal adviser,
   legal counselor, legal expert, legal practitioner, legalist,
   mouthpiece, pleader, proctor, procurator, sea lawyer,
   self-styled lawyer, solicitor



Bouvier's Law Dictionary, Revised 6th Ed (1856):

BARRISTER, English law. A counsellor admitted to plead at the bar.
     2. Ouster barrister, is one who pleads ouster or without the bar.
     3. Inner barrister, a sergeant or king's counsel who pleads within the
bar.
     4. Vacation barrister, a counsellor newly called to the bar, who is to
attend for several long vacations the exercise of the house.
     5. Barristers are called apprentices, apprentitii ad legem, being
looked upon as learners, and not qualified until they obtain the degree of
sergeant. Edmund Plowden, the author of the Commentaries, a volume of
elaborate reports in the reigns of Edward VI., Mary, Philip and Mary, and
Elizabeth, describes himself as an apprentice of the common law.