Mesologarithm
Pronunciation : Mes`o*log"a*rithm
Part of Speech : n.
Etymology : [Meso- + logarithm : cf. F. m?sologarithme.] (Math.)
Definition : Defn: A logarithm of the cosine or cotangent. [Obs.] Kepler. Hutton.
Source : Webster's Unabridged Dictionary, 1913