Translation guide
The navel (belly button) is a body part. In Japanese, the most common word is へそ, used in everyday conversation. There is also a more formal anatomical term さい, and a few related expressions.
Referring to the navel as a physical body part.
The standard, everyday word for 'navel' or 'belly button'. Used by all ages.
赤ちゃんのへそが取れた。
The baby's umbilical cord stump fell off.
Metaphorically referring to the center or heart of a place or thing.
Used metaphorically to mean the center or core of something, similar to 'heart' or 'hub'.
へそ is the everyday word for navel. さい is a technical term used in medical contexts. For daily conversation, always use へそ.
He showed his stomach and pointed at his navel.
Anatomical/medical term for 'navel' or 'umbilicus'. Rarely used in daily conversation.
さいの炎症は臍炎と呼ばれる。
Inflammation of the navel is called omphalitis.
ここが町のへそだ。
This is the center of the town.
北海道のへそと呼ばれる町。
A town called the navel of Hokkaido.
A more literal translation for 'center', but lacks the body-part metaphor. Use when you want a neutral term.
その公園は街の中心にある。
The park is in the center of the city.