'Hypocoristic' definitions:

Definition of 'Hypocoristic'

From: GCIDE

Hypocoristic \Hyp`o*co*ris"tic\, a. [Gr. ?; ? under + ? to caress.] Endearing; diminutive; as, the hypocoristic form of a name. [1913 Webster]
The hypocoristic or pet form of William. --Dr. Murray. [1913 Webster]