坚

strong / solid / firm / unyielding / resolute

variant of 收[shou1]

Tu (ethnic group) / surname Tu

earth / dust / clay / local / indigenous / crude opium / unsophisticated / one of the eight categories of ancient musical instruments 八音[ba1 yin1]

to persevere with / to persist in / to insist on

staunch / strong

to believe firmly / without any doubt

firm / steady / staunch / resolute

firm; resolute; determined

firm / resolute / determined

nut

to hold fast to / to stick to

firm / firmly / hard / stable

hard / solid

firm and substantial / solid

to persevere unremittingly (idiom); to keep going until the end

tough and durable / tenacious

invulnerable, indestructible, impregnable

firm and upright / strong (of currency)

America

unswerving / unflinching

to claim / to insist

firm and persistent / unswerving determination

core / nucleus / backbone