The Collaborative International Dictionary of English v.0.48:

Linger \Lin"ger\ (l[i^][ng]"g[~e]r), v. i. [imp. & p. p.
   Lingered (l[i^][ng]"g[~e]rd); p. pr. & vb. n. Lingering.]
   [OE. lengen to tarry, AS. lengan to prolong, put off, fr.
   lang long. [root]125. See Long, a.]
   To delay; to loiter; to remain or wait long; to be slow or
   reluctant in parting or moving; to be slow in deciding; to be
   in suspense; to hesitate.
   [1913 Webster]

         Nor cast one longing, lingering look behind. --Gray.
   [1913 Webster]

         Perhaps thou linger'st, in deep thoughts detained.
                                                  --Milton.

   Syn: To loiter; lag; saunter; delay; tarry; stop; hesitate.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Linger \Lin"ger\, v. t.
   1. To protract; to draw out. [Obs.]
      [1913 Webster]

            She lingers my desires.               --Shak.
      [1913 Webster]

   2. To spend or pass in a lingering manner; -- with out; as,
      to linger out one's days on a sick bed. --Dryden.
      [1913 Webster]

WordNet (r) 3.0 (2006):

linger
    v 1: remain present although waning or gradually dying; "Her
         perfume lingered on"
    2: be about; "The high school students like to loiter in the
       Central Square"; "Who is this man that is hanging around the
       department?" [syn: loiter, lounge, footle, lollygag,
       loaf, lallygag, hang around, mess about, tarry,
       linger, lurk, mill about, mill around]
    3: leave slowly and hesitantly [syn: tarry, linger]
    4: take one's time; proceed slowly [syn: linger, dawdle]
       [ant: belt along, bucket along, cannonball along,
       hasten, hie, hotfoot, pelt along, race, rush,
       rush along, speed, step on it]
    5: move to and fro; "The shy student lingered in the corner"
       [syn: hover, linger]

Moby Thesaurus II by Grady Ward, 1.0:

87 Moby Thesaurus words for "linger":
   abide, amble, await, bide, bide the issue, carry on, cease not,
   continue, crawl, creep, dally, dawdle, delay, diddle, dillydally,
   dither, doodle, drag, drag along, drag on, drift, dwell on,
   elaborate, endure, fall behind, falter, flag, get behind, go along,
   go on, goof off, halt, hang about, hang around, hang back, hang on,
   harp on, hold everything, hold on, hold steady, hold your horses,
   idle, jog on, keep going, keep on, labor, lag, linger behind,
   linger on, loiter, lollygag, mark time, mope, mosey, muck,
   never cease, pause, persevere, persist, piddle, poke,
   procrastinate, put off, remain, run on, shilly-shally, sit tight,
   sit up, slog on, stagger on, stay, stay on, stay up, stick around,
   straggle, stroll, survive, take time, tarry, temporize, trail,
   trail behind, wait, wait a minute, wait and see, waste time,
   wear on