Stir
Old English styrian, of Germanic origin; related to German stören ‘disturb’.
wiktionary
From Middle English stiren, sturien, from Old English styrian(“to be in motion, move, agitate, stir, disturb, trouble”), from Proto-Germanic *sturiz(“turmoil, noise, confusion”), related to Proto-West Germanic *staurijan(“to destroy, disturb”). Cognate with Old Norse styrr(“turmoil, noise, confusion”), German stören(“to disturb”), Dutch storen(“to disturb”).
From Romani stariben(“prison”), nominalisation of (a)star(“seize”), causative of ast(“remain”), probably from Sanskrit आतिष्ठति(ātiṣṭhati, “stand or remain by”), from तिष्ठति(tiṣṭhati, “stand”).
etymonline
stir (v.)
Old English styrian "to stir, move; rouse, agitate, incite, urge" (transitive and intransitive), from Proto-Germanic *sturjan (source also of Middle Dutch stoeren, Dutch storen "to disturb," Old High German storan "to scatter, destroy," German stören "to disturb"), from PIE *(s)twer- (1) "to turn, whirl" (see storm (n.)). Related: Stirred; stirring. Stir-fry (v.) is attested from 1959.
stir (n.)
"commotion, disturbance, tumult," late 14c. (in phrase on steir), probably from a Scandinavian source, such as Old Norse styrr "disturbance, tumult," from the same root as stir (v.)). The sense of "movement, bustle" (1560s) probably is from the English verb.