c. 1300, conduyt, "conduct, guidance, an escorting party" (a sense now obsolete in this word but preserved in its doublet, conduct), from Old French conduit (12c.) "escort, protection; pipe, channel," from Latin conductus "a leading, a pipe," noun use of past participle of conducere "to lead or bring together; contribute, serve," from assimilated form of com "with, together" (see con-) + ducere "to lead" (from PIE root *deuk- "to lead").
Conduct and conduit differentiated in meaning from 15c. Conduit in the sense "medium or means of conveying" is from mid-14c.; as "pipe or tube or other channel for conveyance of water," late 14c.