The Collaborative International Dictionary of English v.0.48:

Compute \Com*pute"\ (k[o^]m*p[=u]t"), v. t. [imp. & p. p.
   Computed; p. pr. & vb. n. Computing.] [L. computare. See
   Count, v. t.]
   To determine by calculation; to reckon; to count.
   [1913 Webster]

         Two days, as we compute the days of heaven. --Milton.
   [1913 Webster]

         What's done we partly may compute,
         But know not what's resisted.            --Burns.

   Syn: To calculate; number; count; reckon; estimate;
        enumerate; rate. See Calculate.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Compute \Com*pute"\, n. [L. computus: cf. F. comput.]
   Computation. [R.] --Sir T. Browne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

compute
    v 1: make a mathematical calculation or computation [syn:
         calculate, cipher, cypher, compute, work out,
         reckon, figure]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "compute":
   add, add up, algebraize, appraise, appreciate, ascertain, assay,
   assess, calculate, calibrate, caliper, cast, check a parameter,
   cipher, determine, dial, divide, dope out, estimate, evaluate,
   extract roots, fathom, figure, figure in, figure out, gauge,
   graduate, measure, mensurate, mete, meter, multiply, pace, plumb,
   prize, probe, quantify, quantize, rate, reckon, score, size,
   size up, sound, span, step, subtract, sum, survey, take a reading,
   take account of, tally, tot, tot up, total, total up, tote,
   tote up, triangulate, valuate, value, weigh, work out