Fácen-searu

According to the Old English Dictionary:

fácn-searu;

fácen-searu

gen. -searwes; n. A treacherous wile, treachery, machĭnātio dŏlōsa :-- Þurh fácnsearu by treachery, Ps. Th. 55, 1. Gefylled fácensearwum filled with treacherous wiles, Exon. 83 b; Th. 315, 7; Mód. 27. facen-searu