[adjective] [not gradable] [formal]Are there any mitigating circumstances/reasons which might help explain her appalling behaviour?(legal) Duress can be a mitigating circumstance (= reason for considering a crime to be less serious) for crimes which are subject to the death penalty.Compare unmitigated.
MITIGATING
Meaning of MITIGATING in English
Cambridge English vocab. Кембриджский английский словарь. 2012