From Middle English asterten, asteorten, from a- (from Old English ā-) + sterten, equivalent to a- + start.
astart (third-person singular simple present astarts, present participle astarting, simple past and past participle astarted)
- (transitive, obsolete) To cause to start; startle; start up; jump.
- 1590, Edmund Spenser, The Faerie Queene, III.ii:
- oft out of her bed she did astart, / As one with vew of ghastly feends affright [...].
- (intransitive) To start up.
- (obsolete) To get away, escape; escape from.
- (intransitive) To be escaped from.