therewith

c. 1200, from Middle English therwith, from Old English þǣrwiþ (“therewith, in return, in exchange, against”), equivalent to there +‎ with. Cognate with Danish derved (“therewith”), Swedish därvid (“therewith, thereby”). Parallel with Dutch daarmee, German damit (“therewith”), Swedish därmed (“therewith”), though etymologically different. See also theremid.