firm

Synonyms: close close-grained compact compressed concentrated concrete condensed congealed dense fine-grained hard hardened heavy impenetrable impermeable impervious inelastic jelled nonporous refractory rigid set solid solidified stiff sturdy substantial thick tough unyielding

Antonyms: flexible loose slack soft supple weak yielding

Synonyms: anchored bolted braced cemented closed durable embedded fast fastened fixed immobile immovable motionless mounted nailed petrified riveted robust rooted screwed secure secured set settled soldered solid sound spiked stationary steady strong sturdy substantial taut tenacious tight tightened unfluctuating unshakable welded

Antonyms: moving unsettled unstable wavering

Synonyms: abiding adamant bent bound consistent constant dead set on determined enduring established exact explicit fixed flat going hang tough inflexible intent never-failing obdurate persevering persistent prevailing resolute resolved set settled specific stable stand pat stated staunch steadfast steady stipulated strict strong sure tenacious true unbending unchangeable undeviating unflinching unqualified unshakable unshaken unwavering unyielding

Antonyms: alterable changeable indefinite irresolute

Synonyms: association bunch company concern conglomerate corporation crew crowd enterprise gang house megacorp mob multinational organization outfit partnership ring