Be-træppan

According to the Old English Dictionary:

-treppan [be, treppan

be-træppan

to trap] To BETRAP, to entrap; circumvallare :-- Meahton hí ðone here betræppan [betreppan, col. 1] they might entrap the army, Chr. 992; Th. 238, 40, col. 2. be-træppan