A person who shares parenting responsibilities or custody of a child with another parent.
From co- + parent (from Latin parens, one who brings forth). This is a modern formation reflecting contemporary family structures beyond traditional two-parent households.
Coparent is one of the few 'co-' words that's actually growing in modern English—it emerged in the 1980s as custody laws and blended families became more common, showing how language adapts to social change.
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