The Collaborative International Dictionary of English v.0.48:

Seer \Seer\ (s[=e]r), a.
   Sore; painful. [Prov. Eng.] --Ray.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Seer \Se"er\ (s[=e]"[~e]r), n.
   One who sees. --Addison.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Seer \Seer\ (s[=e]r), n. [From See.]
   A person who foresees events; a prophet. --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

seer
    n 1: a person with unusual powers of foresight [syn:
         visionary, illusionist, seer]
    2: an observer who perceives visually; "an incurable seer of
       movies"
    3: an authoritative person who divines the future [syn:
       prophet, prophesier, oracle, seer, vaticinator]

Moby Thesaurus II by Grady Ward, 1.0:

112 Moby Thesaurus words for "seer":
   Cassandra, Don Quixote, Druid, Quixote, TV-viewer, astrologer,
   augur, authority, beholder, bird-watcher, bystander,
   calamity howler, clairvoyant, crystal gazer, daydreamer, divinator,
   diviner, divineress, doctor, dreamer, dreamer of dreams,
   drugstore cowboy, elder, elder statesman, enthusiast, escapist,
   eyewitness, forecaster, foreknower, foreseer, foreshower,
   foreteller, fortune-teller, fortuneteller, gaper, gazer, gazer-on,
   geomancer, girl-watcher, goggler, great soul, guru, haruspex,
   idealist, illuminate, intellect, intellectual, kibitzer, looker,
   looker-on, lotus-eater, lover of wisdom, mahatma, man of intellect,
   man of wisdom, mandarin, master, mastermind, mentor, observer,
   ogler, onlooker, oracle, palmist, perceiver, percipient,
   philosopher, predictor, prefigurer, presager, prognosticator,
   prophesier, prophet, prophet of doom, prophetess, psychic,
   pythoness, rabbi, religious prophets, rhapsodist, rishi, romancer,
   romantic, romanticist, sage, sapient, savant, scholar, seeress,
   sibyl, sidewalk superintendent, soothsayer, spectator, spectatress,
   spectatrix, starets, televiewer, television-viewer, thinker,
   utopian, utopianist, utopianizer, vates, video-gazer, viewer,
   visionary, watcher, weather prophet, wise man, wise old man,
   wishful thinker, witness



Easton's 1897 Bible Dictionary:

Seer
   a name sometimes applied to the prophets because of the visions
   granted to them. It is first found in 1 Sam. 9:9. It is
   afterwards applied to Zadok, Gad, etc. (2 Sam. 15:27; 24:11; 1
   Chr. 9:22; 25:5; 2 Chr. 9:29; Amos 7:12; Micah 3:7). The
   "sayings of the seers" (2 Chr. 33:18, 19) is rendered in the
   Revised Version "the history of Hozai" (marg., the seers; so the
   LXX.), of whom, however, nothing is known. (See PROPHET.)