On-hreósan

According to the Old English Dictionary:

on-hreósan

to fall with violence upon, assail, attack :-- Onhrióseð, anhriósit, anhrísit ingruerit, Txts. 69, 1077. Hú longe onhreósað (onáhreóse, Ps. L.) gé on men quousque inruitis in homines, Ps. Vos. 61, 4. Anhreósaþ inruunt (venti in domum, Mt. 7, 25), Wrt. Voc. ii. 72, 27. Forhergad mid onhreósendum hægle grandine irruente vastata, Gr. D. 57, 5. Onhreósendre mettrumnesse hé geneálǽhte tó deáðe qui ingruente aegritudine ad mortem veniens, 195, 20. Cf. á-hreósan. on-hreosan