Polite word for the buttocks, commonly used in everyday speech and with children.
I wiped the baby's bottom.
bidet function; rear cleansing
Refers specifically to the anal cleansing function on a toilet, often labeled in kana on control panels.
Press the bidet button on the toilet remote.
I spanked the child who had been mischievous.
My bottom hurts from sitting too long.
I pressed the 'bottom' button on the bidet toilet.
I slipped on the ice and landed on my bottom.
My bottom hurts because I've been sitting for a long time.
お尻 is the everyday, polite word for the buttocks, while ヒップ is a loanword favored in fashion, fitness, and body-measurement contexts.
Formed from the honorific prefix お and 尻 (しり, 'buttocks'). The bidet sense is a modern extension from the body part.