The Collaborative International Dictionary of English v.0.48:

Heft \Heft\, v. t. [imp. & p. p. Hefted (Heft, obs.); p. pr.
   & vb. n. Hefting.]
   1. To heave up; to raise aloft.
      [1913 Webster]

            Inflamed with wrath, his raging blade he heft.
                                                  --Spenser.
      [1913 Webster]

   2. To prove or try the weight of by raising. [Colloq.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Heft \Heft\, n.
   Same as Haft, n. [Obs.] --Waller.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Heft \Heft\, n. [From Heave: cf. hefe weight. Cf. Haft.]
   1. The act or effort of heaving; violent strain or exertion.
      [Obs.]
      [1913 Webster]

            He craks his gorge, his sides,
            With violent hefts.                   --Shak.
      [1913 Webster]

   2. Weight; ponderousness. [Colloq.]
      [1913 Webster]

            A man of his age and heft.            --T. Hughes.
      [1913 Webster]

   3. The greater part or bulk of anything; as, the heft of the
      crop was spoiled. [Colloq. U. S.] --J. Pickering.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Heft \Heft\, n.; G. pl. Hefte. [G.]
   A number of sheets of paper fastened together, as for a
   notebook; also, a part of a serial publication.

         The size of "hefts" will depend on the material
         requiring attention, and the annual volume is to cost
         about 15 marks.                          --The Nation.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

heft
    n 1: the property of being large in mass [syn: heft,
         heftiness, massiveness, ponderousness, ponderosity]
    v 1: lift or elevate [syn: heave, heave up, heft, heft
         up]
    2: test the weight of something by lifting it

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "heft":
   avoirdupois, balance, be heavy, beef, beefiness, boost, buoy up,
   carry weight, cast up, counterbalance, deadweight, elevate, erect,
   escalate, fatness, gravity, gross weight, have weight, heave,
   heaviness, heftiness, heighten, heist, hike, hoick, hoist,
   hold the scales, hold up, jerk up, knock up, levitate, lie heavy,
   lift, lift up, liveweight, lob, loft, neat weight, net, net weight,
   overbalance, overweight, perk up, ponderability, ponderosity,
   ponderousness, poundage, raise, raise up, rear, rear up, rise,
   set up, sky, stick up, strike a balance, throw up, tip the scales,
   tonnage, underweight, up, upbuoy, upcast, upheave, uphoist, uphold,
   uplift, upraise, uprear, upthrow, weigh, weigh heavy, weigh in,
   weigh out, weight, weightiness