terebenthene
  Oil of turpentine.

terebinth
  Mediterranean tree (Pistacia terebinthus), a source of tanning material
  and turpentine.

tetter
  Skin diseases (eczema, psoriasis, herpes) that cause eruptions and
  itching.

thrall
  Slave or serf, who is held in bondage.  One intellectually or morally
  enslaved.

thrush
  A contagious childhood disease caused by a fungus, Candida albicans. 
  Causes small whitish eruptions on the mouth, throat, and tongue, and
  usually accompanied by fever, colic, and diarrhea.

thuja (arborvitae)
  A North American or east Asian evergreen tree or shrub of the genus
  Thuja, having flattened branchlets with opposite, scale-like leaves and
  small cones; used as ornamentals and timber.  A similar plant of the
  genus Platycladus or Thujopsis.

thymol
  White, crystalline, aromatic compound, C10H14O, derived from thyme oil
  and other oils or made synthetically and used as an antiseptic, a
  fungicide, and a preservative.

tolu (balsam of tolu, tolu balsam)
  Aromatic yellowish brown balsam from the tolu balsam tree used in cough
  syrups.

tormentil (Potentilla erecta)
  Plant of northern Europe found in clearings and meadows.  The root has
  been used to stop bleeding, for food in times of need and to dye leather
  red.

torpid
  Lacking the power of motion or feeling.

tragacanth
  Thorny shrubs of the genus Astragalus, especially A. gummifer, of the
  Middle East, yielding a gum used in pharmacy, adhesives, and textile
  printing.

trephine
  Surgical instrument with circular edges, used to cut out disks of bone
  from the skull.

trillium (birthroot, wake-robin)
  Plants of genus Trillium, of North America, the Himalaya Mountains, and
  eastern Asia, having a cluster of three leaves and a variously colored,
  three-petaled flower.

trional
  Contains three ethyls.  Similar to sulphonal, used as a hypnotic.

turbinated
  Shaped like a top.  A small curved bone in the lateral wall of the nasal
  passage.

tulle
  Fine, starched net of silk, rayon, or nylon, used for veils, tutus, or
  gowns.

turmeric (tumeric)
  East Indian perennial herb (Curcuma longa) of the ginger family
  (Zingiberaceae) used as a coloring agent, a condiment, or a stimulant. 
  Yellow to reddish brown dyestuff obtained from turmeric.

typhus (prison fever, ship fever, typhus fever.)
  Infectious diseases caused by rickettsia bacteria, especially those
  transmitted by fleas, lice, or mites.  Symptoms are severe headache,
  sustained high fever, depression, delirium, and the eruption of red
  rashes on the skin.

ulster
  Loose, long overcoat made of rugged fabric.