mirific
Working wonders; wonderful.
literary
The Spirit of Grace, in whose mirific power our Savior first, and his Apostls afterward, proclaimed the Gospel […]
1681, Arthur Bury, The Constant Communicant, Oxford: Stephen Botton, Part 4, Chapter 1, p. 192,
Where it comes from
From Latin mirificus and Middle French mirifique.
Adapted from the Wiktionary entry mirific (CC BY-SA 4.0).