Trig. [f. CO- pref. 4 + SECANT. The L. cosecans was used a. 1576 by Rheticus, Opus Palatinum (1596). F. cosécante.] The secant of the complement of a given angle. (Abbreviated cosec.)
1706. in Phillips, Co-secant.
1807. Hutton, Course Math., II. 3. The radius, cotangent, and cosecant [form] another right-angled triangle CDL.
1868. Lockyer, Elem. Astron., 243. AP/PM … is called the cosecant of A (written cosec. A).
