1. triangle; Triangular object 2. Three-person group; Triangle relationship 3. Triangle iron (percussion instrument) 4. Shipbuilding three-wheeled crane 5. Triangle warning sign (indicating faulty vehicle) 6. Triangle plate 7. [T-] astronomical triangle 8. (plural) Military (ancient Britain) Shan Zhi instruments of torture
"Triangulation" also has an English usage to track signals.