'sequentiality' is formed from the adjective 'sequential' plus the noun-forming suffix '-ity'; 'sequential' comes from Late Latin 'sequentialis' ultimately from Latin 'sequens' (present participle of 'sequi'), where 'sequi' meant 'to follow'.

'sequentiality' developed in English by adding the suffix '-ity' to 'sequential' (from Late Latin 'sequentia'/'sequentialis'), which in turn derives from Latin 'sequi' ('to follow').

Initially the Latin root related simply to 'following'; over time the derived English forms came to denote the modern sense of 'orderly succession' or the 'state/quality of following in sequence', which is the current meaning of 'sequentiality'.