The Collaborative International Dictionary of English v.0.48:

Protract \Pro*tract"\, v. t. [imp. & p. p. Protracted; p. pr.
   vb. n. Protracting.] [L. protractus, p. p. of protrahere to
   forth, protract; pro forward + trahere to draw. See
   Portrait, Portray.]
   1. To draw out or lengthen in time or (rarely) in space; to
      continue; to prolong; as, to protract an argument; to
      protract a war.
      [1913 Webster]

   2. To put off to a distant time; to delay; to defer; as, to
      protract a decision or duty. --Shak.
      [1913 Webster]

   3. (Surv.) To draw to a scale; to lay down the lines and
      angles of, with scale and protractor; to plot.
      [1913 Webster]

   4. (Zool.) To extend; to protrude; as, the cat can protract
      its claws; -- opposed to retract.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Protract \Pro*tract"\, n. [L. protractus.]
   Tedious continuance or delay. [Obs.] --Spenser.
   [1913 Webster]

WordNet (r) 3.0 (2006):

protract
    v 1: lengthen in time; cause to be or last longer; "We prolonged
         our stay"; "She extended her visit by another day"; "The
         meeting was drawn out until midnight" [syn: prolong,
         protract, extend, draw out]

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "protract":
   adjourn, chatter, continue, dawdle, defer, delay, drag out, draw,
   draw out, dwell on, elongate, extend, fill out, hang fire, hang up,
   hold, hold off, hold over, hold up, keep, keep alive, keep going,
   keep up, lay aside, lay by, lay over, lengthen, lengthen out,
   let out, linger on, maintain, never finish, pad, perorate,
   perpetuate, pigeonhole, postpone, preserve, procrastinate, produce,
   prolong, prolongate, prorogate, prorogue, pull, push aside,
   put aside, put off, put on ice, recess, reserve, retain, run out,
   set aside, set by, shelve, shift off, sleep on, speak at length,
   spin out, stand over, stave off, stay, strain, stretch,
   stretch out, string out, suspend, sustain, table, take a recess,
   tauten, temporize, tense, tighten, waive