also: ほぞ
noun
navel; belly button
The ordinary body-part meaning. In everyday Japanese it is normally written へそ rather than in kanji.
赤ちゃんのへそをそっと拭いた。
I gently wiped the baby's belly button.
シャツが短くてへそが見えている。
The shirt is short, so his navel is showing.
noun
central bump or hollow; navel-like depression
Only with reading へそ / ヘソ
Used by analogy for a small protrusion or depression in the middle of an object. Restricted this sense to the readings へそ and ヘソ.
リンゴのへそに土が少し残っていた。
A little dirt was left in the apple's navel-like hollow.
noun
Figurative use for the center or most important part of something. Common in set-like expressions such as 日本のへそ and in somewhat informal descriptions of the core of an idea or project.
その町は日本のへそと呼ばれている。
That town is called the center of Japan.
この企画のへそは、地元の人を巻き込むことだ。
The key point of this project is getting local people involved.
Standard kanji spelling, but less common in ordinary writing because usually written in kana.
Older or literary reading of 臍; not used for this word's object-protrusion/depression sense.
Katakana spelling is attested and is often used for emphasis, labels, or a slightly casual visual style.
Rare kanji variant listed; mainly useful for recognition or search.
Means the belly or stomach area as a whole, while へそ specifically means the navel.
A general word for the center of a place, object, or activity; へそ is more image-based and can sound colloquial or nickname-like in figurative uses.
Means the essential point in a more direct, formal way; へそ can mean the core or key point but is less formal and more metaphorical.
へそ is a native Japanese word of uncertain historical derivation. The kanji 臍 is the conventional character for 'navel'; nevertheless usually written in kana.