Noun
A small collar, especially as a kind of necklace of lace, fur etc. for women; a ruff
A small collar of inner petals or leaf-like extensions to the stem.
A type of dahlia having a small collar of short inner petals.
The jagged circle in the mid-diameter of the iris, separating the darker shade of the iris from the lighter shade of the iris.
The rim of loosened keratin surrounding a skin lesion.
(advertising) An advertising card fitted around the neck of a bottle.
Source: en.wiktionary.org