'fastener' originates from Modern English, formed from the verb 'fasten' plus the agentive suffix '-er' (meaning 'one that fastens'). 'Fasten' itself comes from Old English 'fæstnian'.

'fasten' changed from Old English 'fæstnian' (from the adjective 'fæst' meaning 'firm, fixed') to Middle English 'fastenen' and eventually became the modern English verb 'fasten'; the noun 'fastener' developed later by adding '-er' to denote 'that which fastens'.

Initially it referred to the action 'to make firm or fixed' (from the verb); over time it evolved into a noun meaning 'a device that makes things firm or holds them together'.