stufenweise

Adverb

 * 1) gradually
 * 2) progressively, incrementally
 * 1) progressively, incrementally

Adjective

 * 1) step-by-step, stepwise, gradual, staged

Usage notes
Since stufenweise is originally an adverb, its use as an adjective is still frowned upon by some, although it has become common in contemporary German.