baby's first bath
Refers to the first bath given to a newborn baby, a traditional practice in Japan. Often used in the set phrase 産湯を使う (to give a baby its first bath).
Give the baby its first bath.
Standard kanji spelling for a baby's first bath.
Compound of 産 (ubu, 'birth, newborn') + 湯 (yu, 'hot water'). The reading うぶゆ is a straightforward combination of the two elements.