As adjectives the difference between steadfast and relentless
is that steadfast is fixed or unchanging; steady while relentless is unrelenting or unyielding in severity.
steadfast
English
Alternative forms
* stedfast (obsolete)
Adjective
(en-adj)
Fixed or unchanging; steady.
Firmly loyal or constant; unswerving.
Derived terms
* steadfastly
* steadfastness
relentless
English
Adjective
(
en adjective)
Unrelenting or unyielding in severity
Unremitting, steady and persistent
Derived terms
* relentlessness