■ adjective relating to the eye or vision.
■ noun
1》 a lens or other ~al component in an ~al instrument.
2》 archaic or humorous the eye.
3》 Brit. trademark a device fastened to the neck of an inverted bottle for measuring out spirits.
Origin
ME: from Fr. optique or med. L. ~us , from Gk optikos , from optos 'seen'.