shunt

From Middle English schonten, schunten (“to jerk, swerve; to dodge, escape”), either:

possibly a back-formation from Middle English schonen (“to avoid, refuse, hate, fear”), from Old English sċunian, sċyniġan; see shun. Or

an alteration of Middle English *schunden, *schynden, from Old English sċyndan, sċendan (“to hasten, hurry”) (as in āsċyndan (“to remove, take away”), from Proto-West Germanic *skundijan, from Proto-Germanic *skundijaną (“to impel, hasten”).

from unrecorded Old English *sċunettan, a derivative of sċunian (“to shun, avoid”).

As regards the noun sense, compare Middle English shunt (“swerve; sudden jerk”), derived from the verb.