WordNet sense 1 (the section of a band or orchestra that plays brass instruments):

brass section

WordNet sense 2 (the persons (or committees or departments etc.) who make up a body for the purpose of administering something):

administration, establishment, governance, organization, organisation, governing body

WordNet sense 3 (impudent aggressiveness):

boldness, cheek, face, nerve

WordNet sense 4 (a memorial made of brass):

plaque, memorial tablet

WordNet sense 5 (a wind instrument that consists of a brass tube (usually of variable length) that is blown by means of a cup-shaped or funnel-shaped mouthpiece):

brass instrument