Any of several species of Pollenia, especially Pollenia rudis, with the habit of congregating in dwellings over the winter.

(astronomy) an RR Lyrae variable; a type of variable star commonly (but not exclusively) found in globular clusters

Used other than figuratively or idiomatically: see cluster, development. / A housing development built under a cluster zoning ordinance.

(law) A type of zoning ordinance regulating average density rather than the size of each lot, generally requiring some amount of shared open space.

The practice of breastfeeding an infant several times in a short period.

plural of cluster feeding

Biot's respiration

plural of cluster-ball

Alternative spelling of clusterball.

The plant Gastrolobium bennettsianum.