staying the same for a long time; not changing or losing purpose: steadfast beliefs a steadfast friend (Definition of steadfast from the Cambridge Academic Content Dictionary © Cambridge University Press) Steadfast, staunch, steady imply a sureness and continuousness that may be depended upon. Steadfast literally means fixed in place, but is chiefly used figuratively to indicate undeviating constancy or resolution: steadfast in one's faith. 'Steadfast' means resolutely firm and unwavering, as well as loyal and faithful. It is used to describe people who remain committed to their beliefs, goals, or relationships despite obstacles or challenges. steadfast (comparative steadfaster or more steadfast, superlative steadfastest or most steadfast) Fixed or unchanging; steady. Firmly loyal or constant; unswerving. antonym Antonym: infirm steadfast support steadfast commitment