na-adjective, noun which may take the genitive case particle 'no', noun
rigidity; stiffness; uprightness
Describes physical stiffness or rigidity, often in medical or formal contexts. Also used figuratively for moral uprightness or unbending character.
Muscle rigidity occurs.
His rigid attitude caused misunderstandings.
ankylosing spondylitis
tonic-clonic seizure
Compound of 強 (strong, stiff) and 直 (straight, direct). The exact historical derivation is uncertain, but the combination naturally conveys the idea of rigid straightness.