unfaltering

Synonyms: abiding bent on bound bound and determined dead set on enduring firm going all the way indefatigable meaning business mulish never-failing persevering pigheaded resolute set steady stiff-necked stubborn sure tireless unfailing unflagging unflappable unflinching unqualified unquestioning unswerving untiring unwavering wholehearted

Antonyms: faltering unsettled unstable unsteady