Synonyms for Manifestation (same or very similar meaning)
WordNet sense 1 (an appearance in bodily form (as of a disembodied spirit)):
materialization, materialisationWordNet sense 2 (expression without words):
expression, reflection, reflexionWordNet sense 3 (a public display of group feelings (usually of a political nature)):
demonstrationFrom the ODE community, based on WordNetadd/edit