'securely-fastened' originates from the combination of 'securely' and 'fastened', where 'securely' means 'in a secure manner' and 'fastened' means 'attached or fixed'.

'securely-fastened' evolved from the Old English word 'fæstnian', meaning 'to make fast or firm', and 'secure', from Latin 'securus', meaning 'free from care'.

Initially, it meant 'to make something firm', but over time it evolved into its current meaning of 'firmly attached or fixed in place'.