Þrág-bisig

According to the Old English Dictionary:

þrág-bisig

adj. Occupied for a time(?), periodically employed(?) :-- Ic sceal þrágbysig þegne mínnm hýran georne, Exon. Th. 387, 6; Rä. 5, 1. The subject of the riddle is a millstone, and the Latin riddles on which the English one is based seem to suggest that the epithet might refer to running; Aldhelm has: Par labor ambarum ... altera currit; Symphosius: Non desinit ille moveri. þrág, while the verb,þrægan, has a short vowel; and þrág seems always(?) used in the sense of time. þrag-bisig

Related words: Prehn's Rätsel des Exeterbuches. But the verse requires