rock-hard
Firm as stone
Rock-hard means extremely hard, as hard as rock.
The term describes physical hardness—rock-hard abs, rock-hard ice—but extends to anything unyielding: rock-hard determination, rock-hard evidence.
Food that's rock-hard has gone stale or frozen solid: The bread was rock-hard.
Igneous rock, quartz-rich
- concreteSolid building mixture
- diamondCrystallized carbon gemstone
- steelCarbon-hardened iron alloy
- stoneSolid earth fragment
marble · obsidian · basalt · quartzite · tungsten · iron · ceramic · titanium
Solid or resolute
compact · unyielding · impenetrable · tough · hardened · indurated · taut · tight
Solidly built, durable
- resilientAble to recover quickly
- robustStrong and durable
- indestructibleImpossible to damage permanently
- unbreakableImpossible to damage
long-lasting · heavy-duty · reinforced · fortified · wear-resistant · armored · weatherproof · tempered
Unable to bend
- obstinateFirmly refusing to yield
- unyieldingRefusing to give way
- immovableIncapable of being shifted
- intransigentRefusing to compromise
unbending · rigid · bullheaded · headstrong · pigheaded · mulish · willful · obdurate
Firmly committed to purpose
- steadfastFirmly loyal, unshakeable
- unwaveringSteady and unchanging
- firmSolid or resolute
- tenaciousStubbornly determined to continue
unflinching · unshakeable · persistent · committed · strong-willed · single-minded · indomitable · dogged
granite
Igneous rock, quartz-rich
stone · marble · obsidian · basalt · quartzite · tungsten · iron · ceramic · titanium · bedrock
firm
Solid or resolute
dense · compact · unyielding · impenetrable · tough · hardened · indurated · taut · tight · toned
sturdy
Solidly built, durable
- resilientAble to recover quickly
- robustStrong and durable
- indestructibleImpossible to damage permanently
unbreakable · long-lasting · heavy-duty · reinforced · fortified · wear-resistant · armored · weatherproof · tempered · hardwearing
inflexible
Unable to bend
- obstinateFirmly refusing to yield
- unyieldingRefusing to give way
- immovableIncapable of being shifted
intransigent · unbending · rigid · bullheaded · headstrong · pigheaded · mulish · willful · obdurate · implacable
determined
Firmly committed to purpose
- steadfastFirmly loyal, unshakeable
- unwaveringSteady and unchanging
- firmSolid or resolute
tenacious · unflinching · unshakeable · persistent · committed · strong-willed · single-minded · indomitable · dogged · persevering
- hardenedhardened, solidified, petrified, fossilized, calcified
- hyphenated wordsup-to-date, pitch-black, jaw-dropping, round-the-clock, air-conditioned
- stone-relatedgranite, marble, slate, limestone, boulder
- texturessmoothness, smooth, soft, rough, roughness