peculiar

Where it comes from

Peculiar commonly means strange or unusual. Its older meaning was personal: Latin peculiaris meant belonging to one’s private property, from peculium, assets set apart for an individual. In Roman law, a son or enslaved person could administer a peculium even though legal ownership remained with the household head. English first used peculiar for what belonged exclusively or characteristically to someone. If a quality was special to one person or thing, it stood apart from what others shared. “One’s own” could therefore become “uncommon,” and eventually “odd.”

How the meaning developed

Something peculiar was first distinctly one’s own; being unlike everyone else made it unusual later.