Entry 1 sense Webster, 1913 Steadfastness · Stead·fast·ness · IPA /stˈɛdfˌæstnəs/ 01 n. The quality or state of being steadfast; firmness; fixedness; constancy. 1. The quality or state of being steadfast; firmness; fixedness; constancy. “To prove her wifehood and her steadfastness.” — Chaucer.