1) Celtic art 
Triquetra (ə; Latin tri- `three` and quetrus `cornered`) originally meant `triangle` and was used to refer to various three-cornered shapes. Nowadays, it has come to refer exclusively to a particular more complicated shape formed of three vesicae piscis, sometimes with an added circle in or around it. Also known as a `trinity knot,` the d...
triangular-shaped object
• (pl. ) of Triquetrum
The triple goddess symbol representing Maiden, Mother, Crone.