Definition of "detachment"

detachment

/dɪˈtæt͡ʃmənt/

noun
countable and uncountable, plural detachments
1. (uncountable) The action of detaching; separation.
  Quotations
  But the horse has left his mark, for his successor is a mechanical horse designed to a large extent to copy the leading characteristics of the live horse; easy attachment to or detachment from its load, a small turning circle, a small appetite for petrol, but giving a much higher acceleration and speed, and so capable of much greater distances, so that fewer cartage units are required.
  1944 November and December, T. F. Cameron, “Motor and Cartage Working”, in Railway Magazine, page 335
2. (uncountable) The state of being detached or disconnected; insulation.
3. (uncountable) Indifference to the concerns of others; disregard; nonchalance; aloofness.
4. (uncountable) Absence of bias; impartiality; objectivity.
5. (uncountable, military) The separation of a military unit from the main body for a particular purpose or special mission.
6. (countable, military) The unit so dispatched.
  Quotations
  Vietnamese sovereignty over the Paracels dated back at least to the early 19th century, when Emperor Gia-Long sent a detachment to Hoang Sa Island, it remained until the establishment of French protectorate over Annam, when France assumed responsibility for the islands.
  1958, A. V. H. Hartendorp, History of Industry and Trade of the Philippines: The Magsaysay Administration‎, page 218
7. (countable, military) A permanent unit organized for special duties.
8. (countable) Any smaller portion of a main body separately employed.