1. Having three atoms; - said of certain elements or radicals 
2. Having a valence of three; trivalent; sometimes, in a specific sense, having three hydroxyl groups, whether acid or basic

Encyclopedia: Triatomic

• Tsuga canadensis
• Tsuga caroliniana
• Tsuga heterophylla
• Tsuga mertensiana
• tsunami
• Tsung Dao Lee
• tsuris
• Tsushima
• tsutsugamushi disease
• Tswana
• TT
• TTFN
• tu quoque
• Tuamotu Archipelago
• Tuareg
• tuatara
• Tuatha De
• Tuatha Dé Danann
• tub
• tub gurnard
• tub-cart
• tub-thumper
• tuba
• tuba root
• tubal