'non-movable' originates from Latin and Old French elements: the English prefix 'non-' ultimately from Latin 'non' meaning 'not', combined with 'movable' from Latin 'movere' (via Old French 'movable'), where 'movere' meant 'to move'.

'movere' in Latin developed into the Late Latin/Old French form 'movable', which entered Middle English as 'movable'; the negative prefix 'non-' was later attached in Modern English to form the compound 'non-movable'.

Initially the components meant 'not' + 'able to be moved'; over time the compound has retained that basic meaning and is used to describe something fixed or immovable.