| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
sedimentation sed·i·men·ta·tion (sěd'ə-mən-tā'shən, -měn-)
n.
The act or process of depositing or forming a sediment.