mischieve

To destroy.

To damage, do harm to; to injure.

thenne sire Tristram wold make no lenger delayes but lasshed at sir Lamorak / & thus they foughte longe /[…]/ Thenne sir Tristram seid to sir Lamorak in alle my lyf mette I neuer with suche a knyght that was soo bygge and well brethed as ye be / therfore said syre Tristram hit were pyte / that ony of vs both shold here be meschyeued

I have read of Augustine, that once by wandring out of his way, he escaped one who lay in wait to mischieve him;