What is the meaning of Caucus?

A usually preliminary meeting of party members to nominate candidates for public office or delegates to be sent 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.

To meet and participate in a caucus.

To bring into or treat in a caucus.

goblet, cup

caucus

Source: wiktionary.org