The Collaborative International Dictionary
Decursion
Decursion \De*cur"sion\, n. [L. decursio, fr. decurrere. See
Decurrent.]
A flowing; also, a hostile incursion. [Obs.]
--Sir M. Hale.
Wiktionary
decursion
n. 1 (context obsolete English) A flowing. 2 (context obsolete English) A hostile incursion.