Lewis & Short

ădĭtĭo, ōnis, f. [1. adeo].

  1. I. A going to, approach: quid tibi hanc aditio est? (i. e. aditio ad hanc, the verbal substantive with the case of the verb; v. Zumpt, § 681), why do you approach her? Plaut. Truc. 2, 7, 62: praetoris, Dig. 39, 1, 1 al.
  2. II. hereditatis, the entering upon an inheritance (v. 1. adeo, II. A.), Dig. 50, 17, 77 al.