Both Uses of

progressive
in
Brave New World

She stood looking at him, her head on one side, still smiling, but with a smile that became progressively, in face of the Director's expression of petrified disgust, less and less self-confident, that wavered and finally went out.†
p. 150.6 *

progressively = increasingly

Undeterred by that cautionary bruise on their colleague's coccyx, four other reporters, representing the New York Times, the Frankfurt Four-Dimensional Continuum, The Fordian Science Monitor, and The Delta Mirror, called that afternoon at the lighthouse and met with receptions of progressively increasing violence.†
p. 250.9

Definitions:

(1) (progressive as in: progressive decline)
gradually advancing or becoming more severe
(2) (progressive as in: progressive ideas)
of new ideas intended to make things better; or a person favoring such ideas

or (in politics):

progress based on relatively more confidence that changes to institutions will go well (In the U.S., progressives are likely to vote for the Democratic party; though many Democrats do not consider themselves progressives.)
(3) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Progressive tax refers to a system of taxation in which the percent of income taxed increases with higher income. The terms, progressive education or progressive school are sometimes used to refer to more modern educational techniques such as stressing experience and self-expression over rote learning. In 1924, there was a political party in the United States called the Progressive Party. For other more specialized senses (including meanings related to eyeglass lenses, music, and grammar), see a comprehensive dictionary or Wikipedia.