1 to congregate

2 to assemble

3 to mass

4 to gather together

5 to amass

6 to polymerize

1 party

2 gathering

3 to meet

4 to get together

1 communal meal

2 formal dinner of club or group

1 to condense

2 to coagulate

3 coacervation (i.e. form tiny droplets)

4 aggregation

5 coherent

1 convergence

2 to come together

1 destiny will make enemies meet (idiom)

2 (often said about lovers who have a disagreement)

1 to part without hard feelings (idiom)

2 to cut the knot as smoothly as you tied it

1 similar things come together (idiom); like draws like

2 Birds of a feather flock together.

1 Similar things group together, similar people fit together (idiom); Birds of a feather flock together.

1 sand grains accumulate to make a tower a tower (idiom); by gathering small amounts one gets a huge quantity

2 many a mickle makes a muckle