The Collaborative International Dictionary of English v.0.48:

Miff \Miff\ (m[i^]f), n. [Cf. Prov. G. muff sullenness,
   sulkiness, muffen to be silky, muff["i]g sullen, pouting.]
   A petty falling out; a tiff; a quarrel; offense. --Fielding.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Miff \Miff\, v. t.
   To offend slightly. [Colloq.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

miff
    n 1: a state of irritation or annoyance [syn: huff, miff,
         seeing red]
    v 1: cause to be annoyed; "His behavior really miffed me"

Moby Thesaurus II by Grady Ward, 1.0:

87 Moby Thesaurus words for "miff":
   aggravate, altercation, annoy, arouse, badger, bait, be at,
   bedevil, beef, beset, bother, bristle, brown off, bug, bullyrag,
   burn up, chafe, chivy, conniption, devil, discompose, dispute,
   distemper, disturb, dog, dudgeon, embitter, exasperate, exercise,
   falling-out, fash, ferment, fit, fret, fume, get, gripe, harass,
   harry, heckle, hector, high dudgeon, hound, huff, incense, inflame,
   irk, irritate, molest, nag, needle, nettle, nudzh, peeve,
   persecute, pester, pet, pick on, pique, plague, pluck the beard,
   pother, provoke, rankle, resentment, rhubarb, ride, rile, roil,
   ruffle, run-in, set up, snuff, spat, squabble, stew,
   stir the blood, stir up, tease, tiff, torment, try the patience,
   tweak the nose, umbrage, vex, work up, worry