firm Synonyms

solid strong steadfast steady hard unwavering resolute FAST persistent sturdy tough compact stiff loyal tight constant fixed unfluctuating unyielding determined unshakable stable secure rigid unfaltering immovable unswayable tone tightly toned tighter tireless vigorous thickened sure sustained viscid virgate syndicate verified taut tenable tenacious trusty undisputable unfailing viscous unflinching unremitting unlimber