'heretofore' originates from Old English and Middle English elements: Old English 'hēr' (here), the preposition 'to', and 'for(e)' (fore), combined into a phrase meaning 'before this.'

'heretofore' changed from the Middle English phrase 'here to fore' (written as separate words or hyphenated) and eventually became the single modern English adverb 'heretofore'.

Initially it meant 'before this time' in a literal sense, and over time it has retained that core meaning (used in formal or legal contexts) as 'up to now' or 'previously'.