confluence

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A flowing together of two or more streams.
• noun The point of juncture of such streams.
• noun The combined stream formed by this juncture.
• noun A gathering, flowing, or meeting together at one juncture or point.

from The Century Dictionary.

• noun In psychology, the mutual assimilation of mental processes set up by adjacent stimuli: opposed to contrast.
• noun A flowing together; specifically, the meeting or junction of two or more streams of water or other fluids; also, the place of meeting: as, the confluence of the Ohio and the Mississippi: often used figuratively.
• noun A running together of people; an assemblage; a throng; a concourse.
• noun In philoh., the tending toward accordance, or the becoming similar or accordant in form: said of words.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act of flowing together; the meeting or junction of two or more streams; the place of meeting.
• noun Any running together of separate streams or currents; the act of meeting and crowding in a place; hence, a crowd; a concourse; an assemblage.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The place where two rivers, streams, or other continuously flowing bodies of water meet and become one, especially where a tributary joins a river.
• noun The act of combining which occurs at the place where rivers and the like meet.
• noun A convergence or combination of forces, people, or things.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a place where things merge or flow together (especially rivers)
• noun a coming together of people
• noun a flowing together