WordNet sense 1 (a tense of verbs used in describing action that is on-going):

imperfect, continuous tense, imperfect tense, progressive tense

WordNet sense 2 (a person who favors a political philosophy of progress and reform and the protection of civil liberties):

liberalist

WordNet sense 3 (becoming greater or larger):

increasing

WordNet sense 4 (moving forward):

forward, advancing

WordNet sense 5 (ahead of the times):

advanced, forward-looking, modern

WordNet sense 6 (favoring or promoting reform (often by government action)):

reformist, reform-minded

WordNet sense 7 (tolerant of change; not bound by authoritarianism, orthodoxy, or tradition):

liberal