1.  snowball(n = noun.plant) abronia elliptica, sweet sand verbena - plant having heads of fragrant white trumpet-shaped flowers; grows in sandy arid regions;
is a kind of sand verbena

2.  snowball(n = noun.food) - ball of ice cream covered with coconut and usually chocolate sauce;
is a kind of frozen dessert

3.  snowball(n = noun.food) - ball of crushed ice with fruit syrup;
is a kind of frozen dessert

4.  snowball(n = noun.artifact) - snow pressed into a ball for throwing (playfully);
is a kind of ball
Derived form verb snowball₂

1.  snowball(v = verb.change) - increase or accumulate at a rapidly accelerating rate;
is one way to increase
Sample sentences: Something ----s

2.  snowball(v = verb.contact) - throw snowballs at;
is one way to bombard, pelt
Derived form noun snowball₄
Sample sentences: Somebody ----s something

1.  A round mass of snow pressed or roller together, or anything resembling such a mass. [1913 Webster]

2.  The Guelder-rose. [1913 Webster]

3.  a shrub of the genus Viburnum, having large clusters of white flowers. [PJC]

   To pelt with snowballs; to throw snowballs at. [1913 Webster]

1.  To throw snowballs. [1913 Webster]

2.  To increase in magnitude at an accelerating rate, achieving large proportions; -- by analogy with a snowball rolling down a steep hill, causing a large snow slide. [PJC]

snowball, n. & v.
--n.
1 snow pressed together into a ball, esp. for throwing in play.
2 anything that grows or increases rapidly like a snowball rolled on snow.
--v.
1 intr. & tr. throw or pelt with snowballs.
2 intr. increase rapidly.

Idiom:
snowball-tree a guelder rose.

N  assemblage, collection, collocation, colligation, compilation, levy, gathering, ingathering, muster, attroupement, team, concourse, conflux, congregation, contesseration, convergence, meeting, levee, reunion, drawing room, at home, conversazione, assembly, congress, convention, conventicle, gemote, conclave, posse, posse comitatus, Noah's ark, miscellany, collectanea, museum, menagerie, museology, crowd, throng, group, flood, rush, deluge, rabble, mob, press, crush, cohue, horde, body, tribe, crew, gang, knot, squad, band, party, swarm, shoal, school, covey, flock, herd, drove, atajo, bunch, drive, force, mulada, remuda, roundup, array, bevy, galaxy, corps, company, troop, troupe, task force, army, regiment, host, populousness, clan, brotherhood, fraternity, sorority, association, volley, shower, storm, cloud, group, cluster, Pleiades, clump, pencil, set, batch, lot, pack, budget, assortment, bunch, parcel, packet, package, bundle, fascine, fasces, bale, seron, seroon, fagot, wisp, truss, tuft, shock, rick, fardel, stack, sheaf, haycock, fascicle, fascicule, fasciculus, gavel, hattock, stook, accumulation, congeries, heap, lump, pile, rouleau, tissue, mass, pyramid, bing, drift, snowball, snowdrift, acervation, cumulation, glomeration, agglomeration, conglobation, conglomeration, conglomerate, coacervate, coacervation, coagmentation, aggregation, concentration, congestion, omnium gaterum, spicilegium, black hole of Calcutta, quantity, collector, gatherer, whip, whipper in, assembled, closely packed, dense, serried, crowded to suffocation, teeming, swarming, populous, as thick as hops, all of a heap, fasciculated cumulative, the plot thickens, acervatim, tibi seris tibi metis.