твердый — meaning in English

tvyordyy

English meaning

adamant adj Refusing to change one's mind or position; firmly determined.
firm noun A business, especially one run as a partnership, such as a law or accounting practice.
hard adj Solid and firm; not easily broken, cut, or dented.
harsh adj Unpleasantly rough, severe, or unforgiving — used for weather, conditions, sounds, or treatment.
iron noun A common, silvery-grey metal that rusts and is attracted to magnets; the main ingredient of steel.
resolute adj Firmly determined and not easily swayed from a decision or course of action.
solid adjective Firm and stable in structure; not liquid or gas.
stiff adjective Rigid; not easily bent or moved.

твердый is used for these senses in English:

adamant (said of people and their conviction) Firm; unshakeable; unyielding; determined.
firm Steadfast, secure, solid (in position)
firm Durable, rigid (material state).
hard (of water) High in dissolved chemical salts, especially those of calcium.
hard Resistant to pressure; difficult to break, cut, or penetrate.
hard-and-fast (idiomatic, of rules, etc) strictly maintained; not subject to variation
harsh Unpleasantly rough to the touch or other senses.
iron (figuratively) Strong (as of will), inflexible.

adj Refusing to change one's mind or position; firmly determined.
noun A legendary stone or mineral once believed to be unbreakable, historically linked to diamond or lodestone.

noun A business, especially one run as a partnership, such as a law or accounting practice.
adj Solid and steady; not easily moved, shaken, or changed.
adj Hard or resistant to pressure, describing texture.
verb To make something solid, stable, or resistant to pressure.