bushment

And by the way Sir Meliagrance laid in an embushment the best archers that he might get in his country, to the number of thirty, to await upon Sir Launcelot, charging them that if they saw such a manner of knight come by the way upon a white horse, that in any wise they slay his horse, but in no manner of wise have not ado with him bodily, …

The first day of August a bushement of Frenchemen came to the cawsey but a myle and halfe out of Caleys, where they brenned howses, toke many men prisonars, droffe away horses […].