noun
little madam; young wealthy wife
Slang term for a young, fashion-conscious woman married to a high-earning man; often implies a somewhat showy or pampered lifestyle.
あのコマダムはいつも高級ブランドのバッグを持っている。
That little madam always carries a luxury-brand bag.
最近、銀座でコマダム向けのサロンが増えているらしい。
Lately, salons for young wealthy wives seem to be increasing in Ginza.
マダム is a general term for a married woman or madam, while コマダム specifically refers to a young, stylish wife of a wealthy man, often with a slangy, slightly mocking nuance.
Combination of the prefix 小 (こ, 'small, little') and マダム ('madam'), likely a wasei-eigo coinage. The exact origin is uncertain, but it emerged as slang in fashion and lifestyle contexts.