Definition of "orbicularis" [orbicularis]

• In anatomy, a muscle surrounding an orifice, as that of the mouth or eyelids; a sphincter. (noun)

The Century Dictionary (Public Domain)

• "The muscle that controls eye-smiling is called the orbicularis oculi, and its activation has proved to be a reliable indicator of internal happiness or mirth."
• "Squeeze your zigomatic major, squint your orbicularis oculi, and if you really want to get things flowing ... expose your teeth."
• "Mr. JOHN MERCANTI (Chief Engraver, United States Mint): When they do a portrait, I want them to know exactly what the whole muscle structure in the face is, orbicularis oculi, orbicularis oris."