WordNet (r) 3.0 (2006):

sum up
    v 1: give a summary (of); "he summed up his results"; "I will
         now summarize" [syn: sum up, summarize, summarise,
         resume]
    2: be a summary of; "The abstract summarizes the main ideas in
       the paper" [syn: summarize, summarise, sum, sum up]
    3: determine the sum of; "Add all the people in this town to
       those of the neighboring town" [syn: total, tot, tot
       up, sum, sum up, summate, tote up, add, add
       together, tally, add up]

Moby Thesaurus II by Grady Ward, 1.0:

90 Moby Thesaurus words for "sum up":
   abbreviate, abridge, abstract, add up, battologize, bob, boil down,
   capsulize, cast up, cipher up, clip, compress, condense, contract,
   count up, crop, curtail, cut, cut back, cut down, cut off short,
   cut short, detail, digest, dock, elide, epitomize, figure up, fill,
   foot up, foreshorten, give an encore, go over, go through,
   inventory, itemize, iterate, mow, nip, nutshell, pad, poll,
   pollard, practice, prune, reaffirm, reap, reassert, recap,
   recapitulate, recite, reckon up, recount, reduce, rehash, rehearse,
   reissue, reiterate, relate, reprint, restate, resume, retail,
   retell, retrench, review, reword, run over, say over,
   say over again, score up, shave, shear, shorten, snub, stunt, sum,
   summarize, summate, synopsize, take in, tally up, tautologize,
   telescope, tot up, total, total up, tote up, trim, truncate