undeviating

From un- +‎ deviating.

• IPA^(key): /ʌnˈdiːvieɪtɪŋ/

undeviating (comparative more undeviating, superlative most undeviating)

1. That does not deviate, veer or turn aside; unswerving.
2. That does not change; steady.
   • 1837, L[etitia] E[lizabeth] L[andon], Ethel Churchill: Or, The Two Brides. […], volume III, London: Henry Colburn, […], →OCLC, pages 123–124:

     And she had a yet harder lesson to learn—that nothing can supply the place of strong, undeviating principle.