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  
<noun.substance>
<noun.substance>
| Tl |   | 
| atomic number 81 |   | 
| thallium |   | 
semantic pointers
hypernym
substance holonym
