tl

from WordNet (r) 3.0 (2006)

Tl
    n 1: a soft grey malleable metallic element that resembles tin
         but discolors on exposure to air; it is highly toxic and is
         used in rodent and insect poisons; occurs in zinc blende
         and some iron ores [syn: {thallium}, {Tl}, {atomic number
         81}]

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

TL
       Telecommunication Leadership [standard] (QuEST)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

TL
       Transform and Lighting (3D), "T&L"