What 躻 means
Read うつけ, it is a Japanese insult for a fool.
Japanese dictionaries classify 躻 as a kokuji, a kanji made in Japan. It combines 身 (“body”) and 空 (“empty”), suggesting an empty-headed person. A Japanese lexicon cites the related word うつけもの (“fool”) in a mid-Muromachi source (from Japan’s Muromachi period) and gives a 1628 example; those dates belong to the word-family, not necessarily to the written character 躻.
Should I send 躻 to someone?
Only if you mean to call them a fool. It is a pointed insult, not a neutral way to say “silly.” If the recipient does not read Japanese, the insult may be opaque.
A pointed Japanese insult for a fool; not neutral or polite.
Use it only when the insult is deliberate.
Questions people ask
1Why does 躻 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type 躻
躻\8EBBCodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.