1. (adj)former(a) referring to the first of two things or persons mentioned (or the earlier one or ones of several)
"the novel was made into a film in 1943 and again in 1967; I prefer the former version to the latter one"
2. (adj)erstwhile(a), former(a), old, onetime(a), one-time(a), quondam(a), sometime(a) belonging to some priortime "erstwhile friend"; "our former glory"; "the once capital of the state"; "her quondam lover"
3. (adj)former(a), late(a), previous(a) (used especially of persons) of the immediate past "the former president"; "our late President is still very active"; "the previous occupant of the White House"
4. (adj)early(a), former(a), other(a) belonging to the distant past "the early inhabitants of Europe"; "former generations"; "in other times"