Dictionary.net

the member of a group whose duty it is to convene meetings

One who convenes or meets with others.

One who calls an assembly together or convenes a meeting; hence, the chairman of a committee or other organized body.

One who convenes a meeting: the chairman of a committee.

One who calls others together; the chairman of a committee.

n. One who convenes; —the president of a county court, committee, or club, who summons the members, and presides at their meetings.