- of or relating to duty and moral obligation as ethical concepts.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- of or relating to such ethical concepts as obligation and permissibility
- designating the branch of modal logic that deals with the formalization of these concepts
C19: from Greek deon duty, from impersonal dei it behoves, it is binding
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012