TARTAN is a 6 letter word that starts with T.

1. \Tar"tan\, n. [F. tiretane linsey-woolsey, akin to Sp.
   tirita[~n]a a sort of thin silk; cf. Sp. tiritar to shiver or
   shake with cold.]
   Woolen cloth, checkered or crossbarred with narrow bands of
   various colors, much worn in the Highlands of Scotland;
   hence, any pattern of tartan; also, other material of a
   similar pattern.
   
         MacCullummore's heart will be as cold as death can make
         it, when it does not warm to the tartan. --Sir W.
                                                  Scott.
   
         The sight of the tartan inflamed the populace of London
         with hatred.                             --Macaulay.
   
   

2. \Tar"tan\, n. [F. tartane, or Sp., Pg., or It. tartana;
   all perhaps of Arabic origin.] (Naut.)
   A small coasting vessel, used in the Mediterranean, having
   one mast carrying large leteen sail, and a bowsprit with
   staysail or jib.
   
   

A simple language proposed to meet the ironman requirements.

["TARTAN - Language Design for the Ironman Requirements: Reference Manual", Mary Shaw et al, SIGPLAN Notices 13(9):36-58 (Sep 1978)].

an Assyrian word, meaning "the commander-in-chief." (1.) One of Sennacherib's messengers to Hezekiah (2 Kings 18:17). (2.) One of Sargon's generals (Isa. 20:1).