Steartlian

According to the Old English Dictionary:

steartlian

p. ede To kick with the foot, stumble :-- Ðæt ðú ne spear[n]last l steartlest, stærtlige ut non calcitres, Hpt. Gl. 464, 1. [In later English startle is used of quick movement :-- A courser, startling as the fyr, Chauc. Leg. G. W. 1204. Thouȝ ne havest frend that ne wolde fle, come thouȝ stertlinde in the strete, Mapes 335, 24. See also Halliwell's Dict. stertle.] steartlian