Þrýþ-full

According to the Old English Dictionary:

þrýþ-full

adj. Mighty, strong, powerful :-- Fóron æfter burgum þegnas þrýðfulle, oft hí þræce rǽrdon, Exon. Th, 243, 17; Jul. 12. Ic (the devil) bebeóde bearnum mínum, þegnum þrýðfullum, ðæt hié ðé hnǽgon, Andr. Kmbl. 2659; An. 1331. þryþ-full