noun
bone; hard bone
Only when written 硬骨
Literal anatomical sense; refers to bone as a hard tissue. Often used in medical or biological contexts.
硬骨組織の再生には時間がかかる。
Regeneration of bone tissue takes time.
noun, noun which may take the genitive case particle 'no', na-adjective
firmness of character; backbone; unyielding spirit
Figurative use describing a person's strong, principled, and unyielding character. Often used in literary or formal contexts.
彼は硬骨の政治家として知られている。
He is known as a politician of unyielding integrity.
硬骨な態度で交渉に臨んだ。
He approached the negotiations with a firm attitude.
Compound of 硬 (hard) and 骨 (bone). The figurative sense developed from the idea of having a 'hard bone' as a metaphor for an unyielding character.