'post-consonantal' originates from Latin elements: the prefix 'post-' (Latin 'post', meaning 'after') combined with 'consonant' (from Latin 'consonans', meaning 'sounding together').

'consonant' entered English via Latin 'consonans' (through Old French and Middle English), while the prefix 'post-' comes directly from Latin 'post'. The compound 'post-consonantal' was formed in modern English by attaching 'post-' to the adjective 'consonantal'.

Initially it literally meant 'after a consonant'; in linguistic use this original literal sense has been retained and specialized to describe phonetic/phonological position or processes occurring after a consonant.