WordNet (r) 3.0 (2006):

pass up
    v 1: refuse to accept; "He refused my offer of hospitality"
         [syn: refuse, reject, pass up, turn down,
         decline] [ant: accept, have, take]
    2: fail to acknowledge; "he passed me up in the street"

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "pass up":
   abandon, abjure, abstain, abstain from, avoid, brush aside, chuck,
   chuck out, contemn, contradict, cut, cut dead, decline, deny,
   despise, disapprove, discard, disclaim, discount, disdain, dismiss,
   disown, disregard, do without, eschew, except, exclude, forbear,
   forgo, forswear, give the go-by, goldbrick, goof off,
   hold aloof from, hold back, ignore, jump, keep from, leave,
   leave loose ends, leave undone, let alone, let be, let dangle,
   let go, let go by, look right through, make little of, malinger,
   miss, neglect, never touch, not touch, omit, overlook, pass by,
   pass over, pooh-pooh, pretermit, procrastinate, push aside, rebuff,
   recant, refrain, refrain from, refuse, refuse to acknowledge,
   refuse to consider, refuse to recognize, reject, renounce, repel,
   repudiate, repulse, scout, shirk, shove away, shun, skip, slack,
   slight, spare, spurn, stand aloof from, throw away, throw out,
   trifle, turn away, turn out, waive, withhold