Definition of widowing:
(n) :
A person who has lost a spouse and not remarried:
(n) :
A woman whose spouse (traditionally husband) has died (and who has not remarried); a woman in relation to her late spouse; feminine of widower.
(n) :
A person whose spouse is absent:
(n) :
(uncommon) Any person whose spouse has died (and who has not remarried).
(n) :
(by extension, informal, often humorous or sarcastic, in combination) A woman whose husband is often away pursuing a hobby, career, etc.
(v) :
(transitive) To make a widow or widower of someone; to cause the death of the spouse of.