A Shriner is, in basic definition, a member of The Shrine. This means that they are a Mason and by extension that they are male.
In a more philosophical sense, a Shriner is someone who is committed to public works and public service in a largely anonymous capacity; though you will see shriners driving "Tin Lizzys" in parades and wearing Fez'es around, that is really as directly public the individual Shriner gets; the bulk of their works are done in anonymously or in private by way of caring for those in need by either monetary donation or volunteer work for The Shriners Hospitals for Children and other arms of the The Shine that operate in similar capacities.