Adjective
XIth (not comparable)
(rare) 11th; Abbreviation of eleventh.
At the end of the fight, the Nationalist troops had been forced to retreat, abandoning all hopes of a direct assault on Madrid by Casa de Campo, while the XIth Brigade had lost a third of its personnel. Source: Internet
The northern cauldron consisted of the XIth Corps, the central with the VIIIth and LIst Corps, and the southern with the XIVth Panzer Corps and IVth Corps "without units". Source: Internet