The Collaborative International Dictionary of English v.0.48:

Dormant \Dor"mant\, n. [See Dormant, a.] (Arch.)
   A large beam in the roof of a house upon which portions of
   the other timbers rest or " sleep." --Arch. Pub. Soc. --
   Called also dormant tree, dorman tree, dormond, and
   dormer. --Halliwell. Dormer

WordNet (r) 3.0 (2006):

dormant
    adj 1: in a condition of biological rest or suspended animation;
           "dormant buds"; "a hibernating bear"; "torpid frogs"
           [syn: dormant, hibernating(a), torpid]
    2: (of e.g. volcanos) not erupting and not extinct ; "a dormant
       volcano" [syn: dormant, inactive] [ant: active]
    3: lying with head on paws as if sleeping [syn: dormant(ip),
       sleeping]
    4: inactive but capable of becoming active; "her feelings of
       affection are dormant but easily awakened" [syn: abeyant,
       dormant]

Moby Thesaurus II by Grady Ward, 1.0:

125 Moby Thesaurus words for "dormant":
   abeyant, apathetic, asleep, at rest, benumbed, between the lines,
   blase, bored, cataleptic, catatonic, comatose, concealed,
   contemplative, covert, cryptic, dead, dead asleep, debilitated,
   deep asleep, delitescent, do-nothing, dopey, droopy, drugged, dull,
   enervated, esoteric, exanimate, fast asleep, flaked-out, flat,
   foul, groggy, heavy, hebetudinous, hibernating, hidden, idle,
   immobile, in abeyance, in suspense, inactive, inanimate, inert,
   jaded, lackadaisical, laissez-aller, laissez-faire, languid,
   languorous, latent, leaden, lethargic, lifeless, listless, logy,
   lumpish, lurking, meditative, moribund, motionless, muffled,
   mystic, neuter, neutral, numb, obfuscated, oblivious, obscured,
   occult, out, paralytic, paralyzed, passive, phlegmatic, pooped,
   possible, potential, procrastinating, quiescent, quiet, quietist,
   quietistic, resting, sated, sedentary, slack, sleeping, sleepy,
   slow, sluggish, slumbering, slumberous, smoldering, somnolent,
   sound asleep, stagnant, stagnating, standing, standpat, static,
   stationary, still, stultified, submerged, supine, suspended, tame,
   torpid, unaroused, unconscious, under the surface, underlying,
   undisclosed, unexpressed, unmanifested, unmoving, unrevealed,
   vegetable, vegetative, veiled, virtual, wan, weary, world-weary