1. A soft grey malleable metallic element that resembles tin but discolours on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores
   - Tl, atomic number 81

Derived forms: thalliums

Type of: metal, metallic element

Part of: blende, sphalerite, zinc blende

Encyclopedia: Thallium

• inobservant
• inobtrusive
• Inocor
• inoculant
• inoculate
• inoculating
• inoculation
• inoculator
• inoculum
• inodorous
• inoffensive
• inoffensively
• inoperable
• inoperative
• inopportune
• inopportunely
• inopportuneness
• inordinate
• inordinately
• inordinateness
• inorganic
• inorganic chemistry
• inorganic compound
• inorganic phosphate
• inorganically