The name of an ancient writ, which lies when: the lord paramount distrains on the tenant paravail; the latter shall have a writ of mesne against the lord who is mesne. Breve’ de medio, old English law. A writ which was so called, by reason of the words used in the writ, namely, Unde idem A qui medius est inter C et praefatum B; that is, A, who is mesne between C, the lord paramount, and B, the tenant paravail.