'pre-supplied' is formed from the prefix 'pre-' (from Latin 'prae', meaning 'before') combined with 'supply', which ultimately comes from Latin 'supplēre' (or 'supplere'), where 'sup-'/ 'sub-' meant 'under' and 'plēre' meant 'to fill'.

'supply' entered English via Old French (e.g. Old French 'supplier' / 'supplyer') and Middle English 'supplyen', eventually becoming the modern English 'supply'; the prefix 'pre-' from Latin 'prae' was added in English formation to indicate 'before', producing 'pre-supply' and its forms like 'pre-supplied'.

Originally related to the idea of 'filling up' (from Latin roots), the meaning shifted toward 'providing or making available', and in 'pre-supplied' this became specifically 'provided beforehand'.