Used colloquially to describe something silly or nonsensical.

बेवकूफी या निरर्थक

English Usage: That idea was just an upu.

Hindi Usage: वह विचार सिर्फ बेवकूफी थी।

A whimsical term for a gathering or party.

मजेदार स्थिति

English Usage: The children laughed and said "Let's play upu!"

Hindi Usage: बच्चे हंसकर बोले "चलो मजेदार स्थिति खेलते हैं!"

A reference to a state of being in a playful context.