firm Synonyms

strong solid steady unshakable FAST loyal resolute fixed steadfast unwavering unfaltering hard constant unfluctuating stiff tightly tireless tighter tone tight thickened tenacious stubborn sturdy substantial sure sustained syndicate taut tenable toned tough unflinching unlimber unmovable unmoved unrelenting unremitting viscous unswayable vigorous virgate unfailing undisputable true true-blue trusty unappealable unbending uncompromising