From BiblePortal Wikipedia

King James Dictionary [1]

Coptic, a. Pertaining to the descendants of the ancient Egyptians, called Copts, or cophti, as distinct from the Arabians and other inhabitants of modern Egypt. The name is supposed to be taken from Coptos, the metropolis of the Thebaid as Egypt, is probably from that name inclosed, fortified. To inclose, to bind, to fortify. Whatever may be the origin of Copt, the adjective Coptic now refers to the people called Copts, who are Christians, and to their language.

Coptic, n. The language of the Copts.

Webster's Dictionary [2]

(1): (a.) Of or pertaining to the Copts.

(2): (n.) The language of the Copts.