The Collaborative International Dictionary of English v.0.48:

Off \Off\ ([o^]f; 115), adv. [OE. of, orig. the same word as R.
   of, prep., AS. of, adv. & prep. [root]194. See Of.]
   In a general sense, denoting from or away from; as:
   [1913 Webster]

   1. Denoting distance or separation; as, the house is a mile
      off.
      [1913 Webster]

   2. Denoting the action of removing or separating; separation;
      as, to take off the hat or cloak; to cut off, to pare off,
      to clip off, to peel off, to tear off, to march off, to
      fly off, and the like.
      [1913 Webster]

   3. Denoting a leaving, abandonment, departure, abatement,
      interruption, or remission; as, the fever goes off; the
      pain goes off; the game is off; all bets are off.
      [1913 Webster]

   4. Denoting a different direction; not on or towards: away;
      as, to look off.
      [1913 Webster]

   5. Denoting opposition or negation. [Obs.]
      [1913 Webster]

            The questions no way touch upon puritanism, either
            off or on.                            --Bp.
                                                  Sanderson.
      [1913 Webster]

   From off, off from; off. "A live coal . . . taken with the
      tongs from off the altar." --Is. vi. 6.

   Off and on.
      (a) Not constantly; not regularly; now and then;
          occasionally.
      (b) (Naut.) On different tacks, now toward, and now away
          from, the land.

   To be off.
      (a) To depart; to escape; as, he was off without a
          moment's warning.
      (b) To be abandoned, as an agreement or purpose; as, the
          bet was declared to be off. [Colloq.]

   To come off, To cut off, To fall off, To go off, etc.
      See under Come, Cut, Fall, Go, etc.

   To get off.
      (a) To utter; to discharge; as, to get off a joke.
      (b) To go away; to escape; as, to get off easily from a
          trial. [Colloq.]

   To take off To do a take-off on, To take off, to mimic,
      lampoon, or impersonate.

   To tell off
      (a) (Mil.), to divide and practice a regiment or company
          in the several formations, preparatory to marching to
          the general parade for field exercises. --Farrow.
      (b) to rebuke (a person) for an improper action; to scold;
          to reprimand.

   To be well off, to be in good condition.

   To be ill off, To be badly off, to be in poor condition.
      [1913 Webster]

WordNet (r) 3.0 (2006):

off and on
    adv 1: not regularly; "they phone each other off and on" [syn:
           off and on, on and off]

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "off and on":
   alternately, at irregular intervals, at random, back and forth,
   backward and forward, backwards and forwards, brokenly, by catches,
   by fits, by jerks, by snatches, by turns, capriciously, changeably,
   desultorily, disconnectedly, discontinuously, eccentrically,
   erratically, every other, fitfully, haltingly, hitch and hike,
   in and out, in rotation, in snatches, in spots, in turns,
   inconstantly, intermittently, irregularly, jerkily, lurchingly,
   make and break, nonuniformly, on and off, patchily, reciprocally,
   ride and tie, roughly, round and round, seesaw, shuttlewise,
   spasmodically, sporadically, spottily, to and fro, turn about,
   uncertainly, unevenly, unmethodically, unpredictably,
   unrhythmically, unsteadfastly, unsteadily, unsystematically,
   up and down, variably, waveringly, whimsically, wobblingly