'loner' originates from English, specifically the adjective 'lone' plus the agentive suffix '-er', where 'lone' meant 'single, solitary'.

'lone' comes from Middle English (from 'alone'), ultimately from Old English 'ān' meaning 'one'; the agentive suffix '-er' was added in modern English (19th century) to form the noun 'loner'.

Initially related words meant 'single' or 'alone'; over time 'loner' became specialized to mean a person who prefers being alone or avoids socializing.