early 15c., "beneficial, convenient," from Old French commodios and directly from Medieval Latin commodiosus "convenient, useful," from Latin commodus "proper, fit, appropriate, convenient, satisfactory," from com-, here probably an intensive prefix (see com-), + modus "measure, manner" (from PIE root *med- "take appropriate measures"). Meaning "conveniently roomy, spacious" first attested 1550s. Related: Commodiously; commodiousness.