The normal OE sense of this word is 'clothing' (often coupled with 'wiste - food'). The reference is puzzling. Earlier editors (see esp. Swanton's edition) have suggested it refers to either streamers or cords hung from the cross, the 'labarum' described by Eusebius which hung from military standards (see the Latin Hymn :Vexilla Regis where the Cross is adorned with royal purple), the covering which was put over the cross on Good Friday and removed on the Resurrection services of Easter Sunday, or that it is merely another way of describing the 'dress' of gold and jewels/water and blood. (See Farina 1967, Smith 1975 for further suggestions). See Images: Ravenna: Arian Baptistry - Dome Mosaic for a jewelled cross with purple drapery.