ἐνευφραίνομαι
From LSJ
αἰὼν παῖς ἐστι παίζων, πεσσεύων∙ παιδός η βασιληίη → time is a child playing draughts; the kingship is a child's | a life-time is a child playing, playing checkers: the kingship belongs to a child | a whole human life-time is nothing but a child playing, playing checkers: the kingship belongs to a child | lifetime is a child at play, moving pieces in a game; kingship belongs to the child
English (LSJ)
A = εὐφραίνομαι ἐν... LXX Pr.8.31, Ph.1.232, al.