Refers to the external sexual organs; a somewhat formal or euphemistic term.
水着から恥部が見えそうで恥ずかしかった。
I was embarrassed because my private parts were almost visible through the swimsuit.
shameful secret; disgraceful aspect; underbelly
Used figuratively for a hidden, embarrassing, or shameful part of something, such as an organization's dark side or a person's secret shame.
その政治家の恥部が週刊誌に暴露された。
The politician's shameful secret was exposed in a weekly magazine.
会社の恥部を隠蔽しようとした。
They tried to cover up the company's disgraceful aspects.
Compound of 恥 (chi, 'shame') and 部 (bu, 'part'). The literal meaning is 'shameful part'.