'TL' definitions:

Definition of 'Tl'

From: WordNet
noun
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]

Acronyms for 'TL'

From: V.E.R.A.
  • Telecommunication Leadership [standard] (QuEST)
  • Transform and Lighting (3D), "T&L" TL;DR Too Long; Didn't Read (slang, Usenet, IRC)