Synonyms and related words :
abiding, ardent, authentic, bona fide, bound, bound and determined, committed, decided, decisive, dedicated, definite, determined, devoted, earnest, enduring, fervent, genuine, heartfelt, hearty, impassioned, never-failing, obstinate, passionate, persevering, persistent, purposeful, relentless, resolute, resolved, serious, sincere, single-minded, steadfast, steady, tenacious, unfaltering, unfeigned, unqualified, unquestioning, unwavering