vippasīdati : [vi + pa + sad + a] becomes clear or bright; to be joyful.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Vippasīdati [vi+pasīdati] to become bright; fig. to be reconciled or pleased, to be satisfied or happy Dh 82; J i.51; PvA 122 (mukha -- vaṇṇa). Caus. vippasādeti.

Pali-English Dictionary, TW Rhys Davids, William Stede,