indispensable

  • (noun): A thing that is not dispensable; a necessity.
  • (noun): (in the plural) Trousers.
  • (adjective): Not admitting ecclesiastical dispensation; not subject to release or exemption; that cannot be allowed by bending the canonical rules.
  • (adjective): (of duties, rules etc.) Unbendable, that cannot be set aside or ignored.
  • (adjective): Absolutely necessary or requisite; that one cannot do without.
  • The law was moral and indispensable. -Bp. Burnet
  • An indispensable component of a heart-healthy diet.