Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dĭcātĭo, ōnis, f. [1. dico, no. II. B. 1.]. 
- I.  A formal declaration of intention to become a citizen, Cic. Balb. 11 (v. the passage in its connection).
- II.   =  praedicatio, a praising. 
- A.  Prop., Cod. Theod. 9, 3, 2. 
- B.  As a title: tua dicatio, your Reverence, Cod. Theod. 11, 30, 1; Lact. Mort. pers. 48 al.