t t /ˈtiː/

noun

1. A unit of weight equivalent to 1000 kilograms  ( metric ton , MT , t , tonne )
   a unit of weight equivalent to 1000 kilograms
    The truck was carrying a load of 10 tonnes
   The truck was carrying a load of 10 tonnes
   

 T

1. Hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells  ( T , tetraiodothyronine , thyroxin , thyroxine )
   hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells
    Thyroxine is 65% iodine
   thyroxine is 65% iodine
   
2. Thyroid hormone similar to thyroxine but with one less iodine atom per molecule and produced in smaller quantity; exerts the same biological effects as thyroxine but is more potent and briefer  ( liothyronine , T , triiodothyronine )
   thyroid hormone similar to thyroxine but with one less iodine atom per molecule and produced in smaller quantity; exerts the same biological effects as thyroxine but is more potent and briefer
   
3. The 20th letter of the Roman alphabet  ( T )
   the 20th letter of the Roman alphabet
   
4. One of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)  ( deoxythymidine monophosphate , T )
   one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)
   
5. A base found in DNA (but not in RNA) and derived from pyrimidine; pairs with adenine  ( T , thymine )
   a base found in DNA (but not in RNA) and derived from pyrimidine; pairs with adenine