ḿ character /ḿ̩/ spelling unconfirmed
(uppercase)
Definitions
  1. A syllabic letter ⟨m⟩ with high tone letterlowercase
Other entries with this spelling
Wiktionary records 2 entries spelled “ḿ”. You're reading one of them; here are the others.
Source: Wiktionary, where this word is spelled “ḿ”. Reference: en-ḿ-yo-character-193Q9cio