Of all the many nouns referring to a large group of things, one of the most fun is slew, as in "I saw a whole slew of birds in the tree by the river."
American English is constantly evolving, its richness coming from the many languages feeding into it. The noun slew, for instance, is from the Irish Gaelic sluagh, meaning "multitude." As an unrelated verb, it's the past tense of slay.
Primary Meanings of slew
(often followed by `of') a large number or amount or extent
move obliquely or sideways, usually in an uncontrolled manner
n (often followed by `of') a large number or amount or extent
- batch, deal, flock, good deal, great deal, hatful, heap, lot, mass, mess, mickle, mint, mountain, muckle, passel, peck, pile, plenty, pot, quite a little, raft, sight, spate, stack, tidy sum, wad
deluge, flood, inundation, torrent
an overwhelming number or amount
a mass of hay piled up in a barn for preservation