1 a a state of aloofness from or indifference to other people, one's surroundings, public opinion, etc. b disinterested independence of judgement.
2 a the act or process of detaching or being detached. b an instance of this.
3 Mil. a separate group or unit of an army etc. used for a specific purpose.
Etymology: F deacutetachement (as DETACH)
Useful english dictionary. 2012.