Æt-wesan

According to the Old English Dictionary:

æt-wesan

p. ic, he -wæs, pl. -wǽron [æt at, wesan to be] To be present; adesse :-- Wilferþ ætwæs, eác swylce ætwǽron úre brúðru Wilfrid adfuit, adfuerunt et fratres nostri, Bd. 4, 5; S. 572, 12. [Goth. at-wisan.] æt-wesan