According to https://en.wiktionary.org/wiki/%E5%B0%94#Chinese
It is
this character https://en.wiktionary.org/wiki/%E2%BA%88
It simply means knife but the wiktionary entry is very short.
Google translate says that it's meaning is indeed knife and it's read Dao.
However,
According to http://zhongwen.com/bushou.htm
The hat character is ru that means enter. So which one is right?