genital area; private parts
A formal, clinical term for the external genital region. In everyday conversation, more colloquial expressions are often used.
The doctor examined the genital area.
陰部のかゆみが気になる。
I'm concerned about itching in the genital area.
perineal region
Standard kanji spelling for the anatomical term.
Compound of 陰 (いん, 'yin; hidden; private') and 部 (ぶ, 'part; region'), literally 'hidden/private part'. The exact historical derivation is uncertain, but the kanji combination is conventionally associated with the anatomical meaning.