ag·glom·er·ate • v. / əˈgläməˌrāt/ collect or form into a mass or group: [tr.] companies agglomerate multiple sites such as chains of stores | [intr.] these small particles soon agglomerate together.• n. / -rit/ a mass or collection of things: a multimedia agglomerate. ∎  Geol. a volcanic rock consisting of large fragments bonded together.• adj. / -rit/ collected or formed into a mass.DERIVATIVES: ag·glom·er·a·tion / əˌgläməˈrāshən/ n.ag·glom·er·a·tive / -ˌrātiv; -rətiv/ adj.

agglomerate Coarse-grained volcanic rock with rounded to subangular fragments. These fragments are mainly larger than 2 cm in size, but the mixture of fragments is typically ill sorted and the matrix may be fine grained. An agglomerate may be the product of a volcanic explosion and therefore a pyroclastic rock, but often the term ‘agglomerate’ is applied to brecciated volcanic rocks of uncertain origin. Those deposits may range from vent breccias to debris from mudflow or lahar deposits.

agglomerate gather into a mass. XVII. f. pp. stem of L. agglomerāre, f. AG- + glomus ball, mass, partly through F. agglomérer; see -ATE3.
So agglomeration XVIII. — F. or L.

Agglomerate

a group or mass of things loosely thrown or huddled together or gathered into a ball or cluster; a mass of volcanic fragments linked through the action of heat.

Examples: an agglomerate of all duchies, 1865; of all facts, 1831; of volcanic fragments.