Synonyms of firm

1 Syllable: taut, set, hard, stiff, l, loyal, staunch, sound, real, strong, bound, mule, crisp, stark, tough, thick, strict, tight
2 Syllables: stiffest, stony, starker, stiffen, employers, solvent, steely, surer, big-deal, proofer, tautest, jocker, steadiest, steadier, chin-up, dense, true-blue, realest, ferrous, intent, strictest, toughest, stock-still, sturdy, close, steady, surest, tightest, stubborn, irons, bravest, hardier, thicker, stiffer, harden, manful, precast, gloppy, steadfast, starkest, puissant, compact, jelled, strongest, rocker, unswayed, tauter, brass-bound, hell-bent, rooted, ferric, jockstrap, bullhead, firmed, solid, constant, hardens, stauncher, creakier, braver, manlier, employer, mulish, tensest, realer, tenser, harder, healthy, skintight, flinty, stonier, rightist, dogged, steeler, stiffens, colter, sounder, heman, gutsier, staunchest, fixed, lieger, braved, crisper, starching, soundest, concern, manly, creaky, hardest, well-set, jellied, concerns, heavy, clingy, die-hard, candying, gutsy, erect, tougher, thickest, stablest, steelier, studder, rigid, faithful, iron, sturdier, brassbound, stricter, brick-wall, hardiest, stabler, tightly, stronger, hardy, manliest, buckram, firming, sealed, tighter
3 Syllables: inferred, congealed, hard-hearted, durable, agency, stiff-necked, unblenching, true-hearted, appressed, allegiant, condensed, substantial, undecayed, untiring, calloused, reliable, agencies, unshaken, unwilted, stout-hearted, two-fisted, partnership, undaring, factories, unsupple, implicit, diuturnal, severest, adamant, fine-grained, nonporous, shatterproof, compressed, severer, compacting, ruffianly, stabile, riveted, callouses, impervious, fireball, persistent, bulldogged, unblinking, crack-the-whip, unchanged, concrete, workplace, vitrifying, rocklike, consentient, tenacious, vitrified, ironclad, incorrupt, stiffened, hard-boiled, padlocked, motionless, truehearted, hard-shelled, unbending, hard-bitten, unyielding, uncompliant, hard-handed, hardened, vitrify, unflinching, entrenched, deadlocked, beefcake, stiffening, sinewy, densify, strong-minded, factory
4 Syllables: rosy-cheeked, unshakable, immotile, resolute, high-principled, undauntable, indurating, solidifying, refractory, determined, well-constructed, unbreakable, immovable, solidified, inarguable, long-continued, close-grained, impermeable, infrangible, indurate, nonbreakable, erectile, apoplectic, impregnable, monophonic, obdurate, consociation, caseharden, iron-handed, purposive, close-fitting, dictative, dictatorial, peremptory, unforgetful, never-failing, unquestioning, unmovable, positive, solidify, concentrated, inelastic, assertive, purposeful, unfaltering, enterprise, decisive, unwavering, unchangeable, monochrome, single-minded, obstinate, inflexible, indurated, heavy-duty, stabilized, unbendable, able-bodied, solidifies, iron-willed, stabilizing
5 Syllables: undisputable, unadaptable, unpermissive, indissoluble, determinate, incontestable, conglomerated, traditionalist, impenetrable, stabilitate, unassailable, uncompromising, unalterable, inalterable, unhesitating, adamantine, unreconstructed, conservative, establishable
6 Syllables: unintimidated, perseverative, opinionative, traditionalistic