Definition of formations:
(n) :
The act of assembling a group or structure. [from 14th c.]
(n) :
Something possessing structure or form. [from 17th c.]
(n) :
The process during which something comes into being and gains its characteristics. [from 18th c.]
(n) :
(military) An arrangement of moving troops, ships, or aircraft, such as a wedge, line abreast, or echelon. Often "in formation".
(n) :
(sports) An arrangement of players designed to facilitate certain plays.
(n) :
(military) A grouping of military units or smaller formations under a command, such as a brigade, division, wing, etc. [from 18th c.]