'Invariable' definitions:

Definition of 'invariable'

From: WordNet
adjective
Not liable to or capable of change; "an invariable temperature"; "an invariable rule"; "his invariable courtesy" [ant: variable]
noun
A quantity that does not vary [syn: constant, constant quantity, invariable]

Definition of 'Invariable'

From: GCIDE
  • Invariable \In*va"ri*a*ble\, a. [Pref. in- not + variable: cf. F. invariable.] Not given to variation or change; unalterable; unchangeable; always uniform. [1913 Webster]
  • Physical laws which are invariable. --I. Taylor. -- {In*va"ri*a*ble*ness}, n. -- {In*va"ri*a*bly}, adv. [1913 Webster]

Definition of 'Invariable'

From: GCIDE
  • Invariable \In*va"ri*a*ble\, n. (Math.) An invariable quantity; a constant. [1913 Webster]