noun
A usually preliminary meeting of party members to nominate candidates for public office or delegates to be sent to a nominating convention, or to confer regarding policy.
A grouping of all the members of a legislature from the same party.
A political interest group by members of a legislative body.
verb
(intransitive or transitive with with) To meet and participate in a caucus.
(informal, by extension, intransitive) To confer.
(transitive) To bring into or treat in a caucus.