decastellate,v.rare.|dɪˈkæstəleɪt| [f.med.L. dēcastellāre, f. de- I. 6 + castellāre to castellate.] trans. To deprive of its castellation, take away the battlements of. 1880A. T. Drane Hist.St.Cath. Siena 356 To sanction the dismantling, or rather decastellating of one of the fortresses.