Definitions:
happening or developing gradually or in stages

(of a person or idea) favouring social reform

denoting an aspect or tense of a verb that expresses an action in progress, e.g. am writing, was writing.

(of a card game or dance) involving a series of sections for which participants successively change place or relative position.

engaging in or constituting forward motion.

an advocate of social reform

a progressive tense or aspect

each of a set of proofs of colour work, showing all the colours separately and the cumulative effect of overprinting them.