IPA: /əˈvaʊər/
KK: /əˈvaʊər/
A person who openly admits or declares something, especially a belief or opinion.
As an avower of environmental protection, she actively participates in clean-up campaigns.
Avower → It is formed from "avow" (from Old French *avouer*, meaning to acknowledge or confess) and "-er" (meaning a person who). An avower is a person who acknowledges or confesses something openly.
Think of someone who openly 'acknowledges' or 'confesses' something — that's what an avower does.