backends

noun
  1. 1

    The rear, back, or unseen portion (of something).

    โ€œThe back end of the operation is kept out of sight of the customers.โ€

  2. 2

    That part of a hardware or software system that is farthest from the user; the internals rather than the user interface.

  3. 3

    The latter end of any given time, especially the latter part of the year; autumn; late autumn.

Antonyms

Source: https://en.wiktionary.org/wiki/back%20end, https://en.wiktionary.org/wiki/backend, https://en.wiktionary.org/wiki/backends