Define: Accidie

From The Murder Room by P.D. James.

Wasn't accidie, that lethargy of the spirit, one of the deadly sins?

From Merriam-Webster Dictionary:

Main Entry: ac·cid·ie
Function: noun
Date: 13th century

Main Entry: ace·dia
Function: noun
Etymology: Late Latin, from Greek akedeia, from a- + kedos care, grief - more at hate
Date: 1607