noun which may take the genitive case particle 'no'
stepless; continuous; infinitely variable
Describes a mechanism or control that can be adjusted smoothly without fixed steps or discrete levels. Common in technical contexts for volume, speed, or brightness controls.
この照明は無段階で明るさを調節できます。
This light can be adjusted steplessly for brightness.
無段階変速機は、エンジン回転数を最適に保ちます。
A continuously variable transmission keeps the engine speed optimal.
Compound of 無 (mu, 'without') and 段階 (dankai, 'step' or 'stage'). The exact historical derivation is uncertain, but the word follows a common pattern for technical terms.