Forþ-lǽstan

According to the Old English Dictionary:

forþ-lǽstan

p. -lǽste; pp. -lǽsted To follow out, accomplish, fulfil; ăgĕre, perăgĕre :-- Ðæt for intingan ðæs godcundan eges ǽne síþe for his scylde onbryrded ongan, swá he eác eft for intingan ðære godcundan lufan lustfulligende ðam écum médum fæstlíce forþlǽste quod causa divīni tĭmōris sĕmel ob reātum compunctus cœpĕrat, jam causa dīvīni ămōris delectātus præmiis indefessus ăgēbat. Bd. 4, 25; S. 600, 23. forþ-læstan