override v.

Old English ofer "beyond; above, in place or position higher than; upon; in; across, past; more than; on high," from Proto-Germanic *uberi (source also of Old Saxon obar, Old Frisian over, Old Norse yfir, Old High German ubar, German über, Gothic ufar "over, above"), from PIE root *uper "over."

As an adjective from Old English uffera. The senses of "past, done,  finished; through the whole extent, from beginning to end" are attested from late 14c. The sense of "so as to cover the whole surface" is from c. 1400. Meaning "leaning forward and down" is from 1540s. The meaning "recovered from" is from 1929. In radio communication, it is used to indicate the speaker has finished speaking (1926).

Above expresses greater elevation, but not necessarily in or near a perpendicular direction; over expresses perpendicularity or something near it: thus, one cloud may be above another, without being over it. Over often implies motion or extension where above would not; hence the difference in sense of the flying of a bird over or above a house, the hanging of a branch over or above a wall. In such uses over seems to represent greater nearness. [Century Dictionary]

Phrase over and above (mid-15c.) is pleonastic, for emphasis. Adjective phrase over-the-counter is attested from 1875, originally of stocks and shares. To be (someone) all over "be exactly what one expects of (someone)" is by 1721.

Middle English riden, from Old English ridan "sit or be carried on" (as on horseback), "move forward; rock; float, sail" (class I strong verb; past tense rad, past participle riden), from Proto-Germanic *ridan (source also of Old Norse riða, Old Saxon ridan, Old Frisian rida "to ride," Middle Dutch riden, Dutch rijden, Old High German ritan, German reiten), from PIE *reidh- "to ride" (source also of Old Irish riadaim "I travel," Old Gaulish reda "chariot"). Common to Celtic and Germanic, perhaps a loan word from one to the other.

Of a ship, "to sail, float, rock," c. 1300. The meaning "heckle" is by 1912 from earlier sense of "dominate cruelly, have the mastery of, harass at will" (1580s) on the notion of "control and manage," as a rider does a horse, especially harshly or arrogantly. The verb in venery is from mid-13c.

To ride out "endure (a storm, etc.) without great damage" is from 1520s, literal and figurative. To let (something) ride "allow to pass without comment or intervention" is by 1921. To ride herd on "guard and control" is by 1897, from cattle-driving. To ride shotgun "ride in the passenger seat of an automobile" is by 1919, from the custom of having an armed man up beside the driver of a stagecoach to ward off trouble. To ride shank's mare "walk" is from 1846 (see shank (n.)). The ____ rides again cliche is from Hollywood movie titles ("Destry Rides Again," 1939).