indurated

adj 0.875

hardened

adj 0.712

hard-set

adj 0.660

iron-hearted

adj 0.634

hardenable

adj 0.605

ironclad

adj 0.591

hard

adj 0.585

ingrain

adj 0.584

adamantine

adj 0.580

unhardened

adj 0.577

hardheaded

adj 0.568

hard-nosed

adj 0.566

callused

adj 0.564

ingrained

adj 0.559

immured

adj 0.553

hardy

adj 0.553

rock-ribbed

adj 0.552

rigid

adj 0.551

hardhearted

adj 0.550

case hardened

adj 0.549

ossified

adj 0.545

hard put

adj 0.543

obdurate

adj 0.543

unyielding

adj 0.543

rock hard

adj 0.543

enduring

adj 0.542

hard as nails

adj 0.541

sclerosed

adj 0.539

sturdy

adj 0.539

staunch

adj 0.539

inveterate

adj 0.538

adamant

adj 0.536

made of sterner stuff

adj 0.535

forted

adj 0.534

hardpacked

adj 0.533

concreted

adj 0.531

resistant

adj 0.529

urned

adj 0.528

rugged

adj 0.528

olid

adj 0.528

durable

adj 0.528

diehard

adj 0.527

unbending

adj 0.526

coriaceous

adj 0.526

ironbound

adj 0.526

leather-hard

adj 0.526

hardline

adj 0.525

hard-boiled

adj 0.524

perdurable

adj 0.523

corticate

adj 0.523

hard-and-fast

adj 0.522

indelible

adj 0.522

resolute

adj 0.521

ruggedized

adj 0.520

stonelike

adj 0.519

nondeformable

adj 0.519

rigorous

adj 0.518

tough

adj 0.518

calcified

adj 0.518

steadfast

adj 0.518

nitrided

adj 0.517

reinforced

adj 0.517

dour

adj 0.515

adust

adj 0.514

stiff

adj 0.513

honed

adj 0.511

ulcerate

adj 0.511

inexorable

adj 0.510

concrete

adj 0.510

hidebound

adj 0.510

indomitable

adj 0.509

set in stone

adj 0.509

incrassate

adj 0.508

flinty

adj 0.508

ungirt

adj 0.508

inflexible

adj 0.507

obstinate

adj 0.507

arduous

adj 0.507

refractory

adj 0.506

iron

adj 0.506

sclerotic

adj 0.505

bullheaded

adj 0.505

stalwart

adj 0.503

forged

adj 0.502

hardball

adj 0.502

incuse

adj 0.502