(1):
(n.) A number of things of the same kind growing together; a bunch.
(2):
(n.) A number of similar things collected together or lying contiguous; a group; as, a cluster of islands.
(3):
(n.) A number of individuals grouped together or collected in one place; a crowd; a mob.
(4):
(v. t.) To collect into a cluster or clusters; to gather into a bunch or close body.
(5):
(v. i.) To grow in clusters or assemble in groups; to gather or unite in a cluster or clusters.