The Collaborative International Dictionary of English v.0.48:

Reviewer \Re*view"er\, n.
   One who reviews or reexamines; an inspector; one who examines
   publications critically, and publishes his opinion upon their
   merits; a professional critic of books.
   [1913 Webster]

WordNet (r) 3.0 (2006):

reviewer
    n 1: someone who reads manuscripts and judges their suitability
         for publication [syn: reviewer, referee, reader]
    2: a writer who reports and analyzes events of the day [syn:
       commentator, reviewer]

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "reviewer":
   advertising writer, analysis, annalist, annotator, art critic,
   audit, author, authoress, belletrist, bibliographer, book reviewer,
   captious critic, carper, caviler, censor, censurer, checkup,
   coauthor, cognoscente, collaborator, columnist, comment,
   commentator, commenter, compiler, composer, connoisseur,
   copywriter, creative writer, critic, criticaster, criticizer,
   critickin, criticule, critique, dance critic, diarist,
   drama critic, dramatist, editor, editorial writer, editorialist,
   encyclopedist, essayist, expositor, expounder, faultfinder,
   free lance, free-lance writer, ghost, ghostwriter, glossarist,
   glossographer, humorist, inditer, inspection, leader writer,
   literary artist, literary craftsman, literary critic, literary man,
   litterateur, logographer, magazine, magazine writer,
   man of letters, monographer, muckraker, music critic, news analyst,
   newspaper, newspaperman, notice, novelettist, novelist, organ,
   pamphleteer, penwoman, periodical, poet, prose writer, publicist,
   recension, reconsideration, redraft, reflection, rescript,
   retrospect, retrospection, revisal, revise, revision, scan,
   scenario writer, scenarist, scholiast, scribe, scriptwriter,
   scrutiny, second thought, short-story writer, smellfungus,
   social critic, storyteller, study, survey, technical writer,
   textual critic, view, word painter, wordsmith, writer