▪ I. cosine Trig.
(ˈkəʊsaɪn)
[mod. f. co- prefix 4 + sine. The L. cosinus occurs in Gunther Canon Triangulorum (1620); F. cosine.]
The sine of the complement of a given angle. (Abbrev. cos.)
| 1635 I. W. Sciographia 44 As the Radius Is to the cosine of the angle given. 1726 tr. Gregory's Astron. I. 141 The Co-sine of the Angle. 1880 Haughton Phys. Geog. iii. 123 The mean annual evaporation..varies as the cosine of the latitude. |
| attrib. 1881 Nature XXV. 167 Integrators were of three kinds: (1) radius machines, (2) cosine machines, (3) tangent machines. |
▪ II. cosine, cosiner
obs. ff. cousin, cozener.