Lewis & Short

prōpugnātĭo, ōnis, f. [propugno].

  1. I. A fighting for, defence of a place (post-class.), Val. Max. 5, 1, 4 ect.
  2. II. A defence, vindication (class.): with the gen. or pro: propugnatio ac defensio dignitatis tuae, Cic. Fam. 1, 7, 2: propugnatio pro ornamentis tuis, id. ib. 5, 8, 1: ne mea propugnatio ei potissimum defuisse videatur, id. Sest. 2, 3.