Any grouping or close arrangement of individual flowers that is not dense and continuous.
A group of small items which cling together.
A significant subset in a Statistical sample, e.g. of numbers of people affected by a particular disease or condition.
In statistical terms a group of subjects, closely linked in time and/or place of occurrence. For example, geographical clusters of leukaemia have been found — that is, an unexpectedly large number of persons with the disease who live in close proximity. Much research goes into trying to discover the cause of clusters but sometimes they appear to have occurred randomly.
A closely grouped series of events (e.g., cases of a disease) with well-defined distribution patterns in relation to time, place, or risk factor exposure.