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.
He showed his stomach and pointed at his navel.
Anatomical/medical term for 'navel' or 'umbilicus'. Rarely used in daily conversation.
Inflammation of the navel is called omphalitis.
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'.
This is the center of the town.
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.
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.
その公園は街の中心にある。
The park is in the center of the city.