IPA: /məˈnɒɡəmɪst/
KK: /məˈnɑgəmɪst/
A person who has only one partner in a romantic relationship at a time.
She is a monogamist who believes in having one partner for life.
Monogamist → It is formed from "mono-" (from Greek "monos", meaning single or alone) and "gamia" (from Greek "gamos", meaning marriage). The word "monogamist" refers to a person who is married to one partner at a time.
Think of 'mono-' meaning 'single' and 'gamos' meaning 'marriage' — a monogamist is someone who is married to just one person.