Definition of mistreater in US English:

mistreater

noun

US
informal, especially
  • A person who mistreats (someone or something); (specifically in blues lyrics) a person who abandons or otherwise mistreats a lover.

Origin

1920s; earliest use found in Carl Van Vechten (1880–1964), writer and photographer. From mistreat + -er.

Pronunciation

mistreater

/ˌmɪsˈtriːtə/