former

Etymology 1

Inherited from Middle English former, comparative of forme (“first”), from Old English forma (“first”), descended from Proto-Germanic *frumô. Parallel to prior (via Latin), as comparative form from same Proto-Indo-European root. Related to first and fore (thence before), from Proto-Germanic.

adj

1. Previous.
   A former president;  the former East Germany
   The former-slaves-turned-abolitionists Quobna Ottobah Cugoano and Olaudah Equiano were the chief organizers of the Sons of Africa. 2007, Junius P. Rodriguez, Encyclopedia of Emancipation and Abolition in the Transatlantic World
2. First of aforementioned two items. Used with the, often without a noun.
   The former is a good idea but the latter is not.
   We have two cars, a red one and a blue one. We won the former on a game show.

Etymology 2

Inherited from Middle English formere; synchronically form + -er.

noun

1. Someone who forms something; a maker; a creator or founder.
   Dave was the former of the company.
2. An object used to form something, such as a template, gauge, or cutting die.
   The brick arch was built using a wooden former.
3. (chiefly Britain, used in combinations) Someone in, or of, a certain form (class).
   Fifth-former.
   Sixth-former.