orbiculus/or·bic·u·lus/ (or-bik´u-lus) pl. orbi´culi [L.] a small disk.
orbiculus(or-bik'u-lus) plural.orbiculi [L., little circle]
Muscle surrounding an orifice; a sphincter muscle.
The portion of the ciliary body consisting of a bandlike zone lying directly anterior to the ora serrata. Synonym: ciliary ring
The circular muscle surrounding the mouth. It is a muscle of facial expression, innervated by the facial nerve.