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

'Securely' and 'settled' have been used in English since the Middle Ages, with 'securely' deriving from the Latin 'securus' meaning 'free from care' and 'settled' from the Old English 'setlan' meaning 'to place or fix'.

Initially, 'securely-settled' meant 'firmly placed', and this meaning has largely remained the same in modern usage.