tach- or tacho- or tachy- [from Greek tachos speed] Swift, rapid, accelerated (tachygenesis).

taen- or taenio- or taeno- or ten- [from Greek tainia band, headband] Denotes tapeworm(s) (teniform, teniasis).

tars- or tarso- [from Greek tarsos podos flat of the foot] Denotes the tarsus (tarsotibial).

taut- or tauto- [from Greek tautos the same, identical] Identical (tautomerism).

tax- or taxo- [from Greek taxis arrangement, order] Denotes arrangement or ordering (taxonomy).

teg- or tegu- [from Latin tegmen covering, protection; clothing, armor, skin, shell, husk] Covering, skin, armor (tegmen).

tel- or tele- or telo- [from Greek telos end] End, completion (telomere, telophase).

tele- [from Greek tele distant] Distant (teleceptor).

ten- See: taen-.

tera- [prefix in International System of Units] trillion (10¹²) (terabyte).

tetr- or tetra- [from Greek tetra four] Four, having four parts (tetramer, tetraploid, tetrapod).

tetrahydr- or tetrahydro- [tetra- + hydro-] Indicates a molecule containing four hydrogen atoms (tetrahydrofolate).

thec- or theci- or theco- [from Latin theca case, box, cover, envelope, container] Sac, capsule, sporecase (theca).

therio- [from Greek therion wild animal] Beast, mammal (theriomorph).

therm- or thermo- [from Greek therme heat] Heat, hot (thermolabile).

thi- or thio- [from Greek theion sulfur] Sulfur (thiamin, thiophil).

thorac- or thoraco- [from Latin thorax chest] Chest (thoracoepigastric).

thromb- or thrombo- [from Greek thrombos lump, clot of blood] Denotes a thrombus (thrombocyte, thrombosis).

thyr- or thyreo- or thyro- or thyroid- [from Greek thyreos oblong shield] Refers to the thyroid gland (thyrohyoid, thyroidectomy) or, more broadly, to anything shield-shaped (thyroid).

tibi- or tibio- [from Latin tibia pipe, shinbone] Denotes the tibia (tibiofemoral).

toco- (also, rarely: toko-) [from Greek tokeus father, sire] Denotes birth (tocology).

tono- [from Greek tonos pressure] Pressure (tonoplast, tonotaxis).

tox- or toxi- or toxo- [from Greek toxon bow] (1) arched, bowlike (Toxodonta) (2) arrow-shaped (Toxoglossa).

tox- or toxi- or toxic- or toxico- or toxo- [from Latin toxicum poison] Poisonous, toxic (toxicity).

trache- or tracheo [from Greek trachelos throat, neck] Relating to the trachea (trachealgia).

trachel- or trachelo [from Greek trachelos throat, neck] Denotes the neck (trachelomastoid).

trans- [from Latin trans across, beyond, on the other side] Across (transfection, transposon).

tri- [from Greek tri thrice] Three, triple (trichocyst).

trich- or tricho- [from Greek thrix the hair of the head] Hair, filament (tricuspid).

tripl- or tripla- or tripli- or triplo- [from Greek triploos threefold, triple] Triple (triploblastic, triploid).

troph- or tropho- [from Greek trophe nourishment, food] Relating to nutrition (trophoblast).

trop- or tropo- [from Greek tropos turn, direction, way] turn, rotation (tropometer).

trop- or tropa- [from tropine] (1) tropine; (2) atropine.

trypan- or trypano- [from Latin trypanon auger] (1) borer, auger, spiral (Trypanosoma); (2) trypanosome (trypanosomiasis).

tubo- [from Latin tubus pipe, trumpet] Denotes a tube (tuboperitoneal).

tympan- or tympano- [from Latin tympanus drum] Relating to the tympanic membrane (tympanotomy).