Definition of "Former" :

noun: the first of two or the first mentioned of two

"Tom and Dick were both heroes but only the former is remembered today."

adjective: 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."

adjective: belonging to the distant past

"Former generations."

adjective: belonging to some prior time

"Our former glory."

adjective: (used especially of persons) of the immediate past

"The former president."