The Collaborative International Dictionary of English v.0.48:

Humanist \Hu"man*ist\ (h[=u]"man*[i^]st), n. [Cf. F. humaniste.]
   1. One of the scholars who in the field of literature proper
      represented the movement of the Renaissance, and early in
      the 16th century adopted the name Humanist as their
      distinctive title. --Schaff-Herzog.
      [1913 Webster]

   2. One who pursues the study of the humanities, or polite
      literature.
      [1913 Webster]

   3. One versed in knowledge of human nature.
      [1913 Webster]

   4. A person with a strong concern for human welfare,
      especially one who emphasizes the dignity and worth of
      individual people, rejecting claims of supernatural
      influences on humans, and stressing the need for people to
      achieve improvement of society and self-fulfillment
      through reason and to develop human-oriented ethical
      values without theism; an adherent of humanism.
      [PJC]

WordNet (r) 3.0 (2006):

humanist
    adj 1: of or pertaining to Renaissance humanism; "the humanistic
           revival of learning" [syn: humanistic, humanist]
    2: of or pertaining to a philosophy asserting human dignity and
       man's capacity for fulfillment through reason and scientific
       method and often rejecting religion; "the humanist belief in
       continuous emergent evolution"- Wendell Thomas [syn:
       humanist, humanistic]
    3: pertaining to or concerned with the humanities; "humanistic
       studies"; "a humane education" [syn: humanist,
       humanistic, humane]
    4: marked by humanistic values and devotion to human welfare; "a
       humane physician"; "released the prisoner for humanitarian
       reasons"; "respect and humanistic regard for all members of
       our species" [syn: human-centered, human-centred,
       humanist, humanistic, humanitarian]
    n 1: a classical scholar or student of the liberal arts
    2: an advocate of the principles of humanism; someone concerned
       with the interests and welfare of humans [syn: humanist,
       humanitarian]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "humanist":
   academician, bookman, classicist, clerk, colossus of knowledge,
   esprit fort, freethinker, genius, giant of learning,
   latitudinarian, learned clerk, learned man, literary man,
   litterateur, lover of learning, man of learning, man of letters,
   mastermind, mine of information, philologist, philologue,
   philomath, philosophe, philosopher, polyhistor, polymath, pundit,
   savant, scholar, scholastic, schoolman, secular humanist, student,
   walking encyclopedia