1530s, "act of moving on water in ships or other vessels," from French navigation (14c.) or directly from Latin navigationem (nominative navigatio) "a sailing, navigation, voyage," noun of action from past-participle stem of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" (from PIE root *nau- "boat") + root of agere "to set in motion, drive, drive forward" (from PIE root *ag- "to drive, draw out or forth, move"). Meaning "science or art of directing the course of vessels as they sail" is from 1550s.
The management of the sails, etc., the holding of the assigned course by proper steering, and the working of the ship generally pertain rather to seamanship, though necessary to successful navigation. The two fundamental problems of navigation are the determination of the ship's position at a given moment, and the decision of the most advantageous course to be steered in order to reach a given point. [Century Dictionary]
mid-15c., "affording passage to ships," from Old French navigable (14c.) or directly from Latin navigabilis, from navigat-, past-participle stem of navigare "to pass over in a ship" (see navigation). Related: Navigability.
1580s, "one who navigates, one who directs the course of a ship," from Latin navigator "sailor," agent noun from navigat-, stem of navigare "to sail, sail over" (see navigation). Meaning "laborer employed in excavating a canal" is by 1775, from sense in inland navigation "communication by canals and rivers" (1727), later extended to those engaged in making railroads. In England, navigation was used in the sense of "an artificial waterway, or a part of a natural one that has been made navigable" by 1720.
1580s, "move from place to place in a ship, sail" (intrans.), a back-formation from navigation, or else from Latin navigatus, past-participle of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" (from PIE root *nau- "boat") + root of agere "to set in motion, drive, drive forward" (from PIE root *ag- "to drive, draw out or forth, move"). Transitive sense of "to pass over in a ship or ships, sail on" is from 1640s; that of "to steer, direct, or manage in sailing" is from 1660s. Extended to balloons (1784) and later to aircraft (1901). Related: Navigated; navigating.
It forms all or part of: aeronautics; aquanaut; Argonaut; astronaut; cosmonaut; nacelle; naval; nave (n.1) "main part of a church;" navicular; navigate; navigation; navy; naufragous; nausea; nautical; nautilus; noise.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit nauh, accusative navam "ship, boat;" Armenian nav "ship;" Greek naus "ship," nautes "sailor;" Latin navis "ship;" Old Irish nau "ship," Welsh noe "a flat vessel;" Old Norse nor "ship."