To bestir is to rouse yourself into activity. Bestir yourself, bestirred himself at last, hardly bestir themselves.
It is reflexive almost always, so you bestir yourself and nobody bestirs anything else. It is deliberately old-fashioned and is used now with a note of irony about somebody slow to act.
1verbbestirTo rouse yourself into activity.
“It was noon before he could bestir himself to get out of bed.”
bestir is a rousing.
Old English bestyrian is be- plus stirian, to stir.
Old English
bestyrian
Middle English
bestyrien
English, today
bestir
From Middle English bestyrien, from Old English bestyrian. From Middle English bestyrien, bestirien, from Old English bestyrian (“to heap up, pile up”), equivalent to be + stir.
Etymology from Wiktionary, CC BY-SA