The term PREFIX WITH DUCT can be solved by two three-letter words, OVI and VIA. OVI is a Latin prefix meaning 'OVER' or 'ABOVE, ' while VIA is a Latin prefix meaning 'by way of.' Both of these prefixes can be used to modify the word 'DUCT, ' which is a tube or passageway for air, water, or other substances. Therefore, the phrase PREFIX WITH DUCT could refer to an 'OVER DUCT' or a 'by way of DUCT, ' depending on which prefix is used.