硬質|こうしつkoushitsu[0]heiban (flat)

1. no-adjectivehardness; stiffness

• Synonym硬さかたさNeutralA neutral noun for hardness as a degree or measurement; unlike 「硬質」, which labels a category of material rather than a quantity.
• SynonymハードCasualA colloquial loanword covering hard, tough or difficult things and also hardware; much broader in range than 「硬質」.
• Synonym硬いかたいNeutralThe everyday adjective for hard things that keep their shape; the broadest term here, covering texture, stiffness and more.
• Synonym硬こうWrittenA rare written noun for the property of being hard and resisting bending or breaking; more literary than 「硬質」.
• Related頑丈がんじょうNeutralA neutral word for the solid, sturdy build of objects or the body; stresses being well-made and durable rather than hard.
• Related丈夫じょうぶNeutralA neutral word for robust health or durable, sturdy things; about strength and durability rather than hardness of material.
• Related強固きょうこWrittenWritten/formal prose for firm, unshakable things, as in 「強固な地盤」 or 「強固な意志」; about firmness and stability, not texture.
• Related剛ごうWrittenWritten/formal prose for strength and boldness; stresses toughness and courage of spirit rather than the physical hardness of 「硬質」.
• Related堅牢けんろうWrittenWritten/formal prose for buildings and structures that are solid and will not fail; about sturdiness, not material hardness.
• Antonym柔らかいやわらかいNeutralThe everyday antonym: soft, gentle and pliable to the touch; contrasts with the hardness 「硬質」 describes.
• Antonym軟質なんしつWrittenWritten/formal prose antonym for softness of a material; the direct opposite of 「硬質」.

Use 「硬質」 for hard materials and textures, often in compounds like 「硬質ガラス」 or 「硬質な文体」. In everyday speech say 「硬い」; for sturdy, durable things or people use 「丈夫」 or 「頑丈」. The written opposite is 「軟質」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 質しつが硬かたいこと。