to skip about, to dance for joy
儛 centers on joyful, lively movement: skipping about and dancing with happiness.
儛 combines 亻 (person) with 舞 (dance), suggesting a person dancing. 舞 itself is a pictograph of a dancer with feet and flowing sleeves. The exact historical development of 儛 as a separate character is uncertain; it may be a variant or elaboration of 舞.
A person 亻 performing the dance 舞: someone skipping and leaping for joy.
For ブ, imagine a dancer moving to a booming beat: boom -> ブ, and the person 亻 dances 舞 with joy.