'prestatutory' originates from Modern English, specifically formed from the prefix 'pre-' (from Latin 'prae-') meaning 'before' and the adjective 'statutory' (from Latin 'statutum') meaning 'established by statute'.

'statutory' developed from Latin 'statutum' (past participle of 'statuere', 'to set up'), passed into Old French/Anglo-Norman as 'statut' and then into Middle English; the combining prefix 'pre-' (from Latin 'prae-') was later attached in Modern English to form 'prestatutory'.

Initially the elements meant 'before' + 'established by statute'; over time the combined form has come to mean 'existing or taking effect prior to statutory law or regulation'.