errant

Etymology

From Middle English erraunt [and other forms], from Anglo-Norman erraunt, from Old French errant, the present participle of errer (“to walk (to); to wander (to); (figuratively) to travel, voyage”), and then: * from Vulgar Latin iterāre (compare Late Latin itinerāre, itinerāri (“to travel, voyage”)), from Latin iter (“a route (including a journey, trip; a course; a path; a road)”), ultimately from Proto-Indo-European *h₁ey- (“to go”); and * from Latin errantem, the accusative feminine or masculine singular of errāns (“straying, errant; wandering”), the present active participle of errō (“to rove, wander; to get lost, go astray; to err, wander from the truth”), ultimately from Proto-Indo-European *h₁ers- (“to flow”). Doublet of arrant.

adj

1. Straying from the proper course or standard, or outside established limits.
   They were all doomed to be disappointed, however, for the errant engine decided at Stanley junction to spend the remainder of its crowded hour of freedom on the Aberdeen line, and finally came to rest, short of breath, in the dip between Ballathie and Cargill, near the bridge over the Tay. 1941 October, “Notes and News: A Highland Runaway”, in Railway Magazine, page 469
2. Roving around; wandering.
3. Prone to making errors; misbehaving.
   We ran down the street in pursuit of the errant dog.
4. (chiefly with a negative connotation, obsolete) Obsolete form of arrant (“complete; downright, utter”).

noun

1. A knight-errant.