Merriam-Webster Collegiate Dictionary - swerve

 verb  (~d; swerving)  Etymology: Middle English, from Old English sweorfan to wipe, file away; akin to Old High German swerban to wipe off, Welsh chwerfu to whirl  Date: 14th century  intransitive verb to turn aside abruptly from a straight line or course ; deviate  transitive verb to cause to turn aside or deviate  • ~ noun Synonyms:  ~, veer, deviate, depart, digress, diverge mean to turn aside from a straight course. ~ may suggest a physical, mental, or moral turning away from a given course, often with abruptness ~d to avoid hitting the dog. veer implies a major change in direction at that point the path veers to the right. deviate implies a turning from a customary or prescribed course never deviated from her daily routine. depart suggests a deviation from a traditional or conventional course or type occasionally departs from his own guidelines. digress applies to a departing from the subject of one's discourse a professor prone to digress. diverge may equal depart but usually suggests a branching of a main path into two or more leading in different directions after school their paths diverged.