adverb, adverb taking the と particle

Usually written with kana alone.
  1. very, extremely, surprisingly, considerably, awfully, terribly.

adjectival noun or quasi-adjective

Usually written with kana alone.
  1. terrible, horrid, contemptible, reprehensible.
  2. remarkable, extraordinary.

Variations

Pronunciation Kanji Kana Is Common
 
 
 
 
ずいぶん
随分 ずいぶん
 
 
ずい分 ずいぶん
隨分 ずいぶん