Plural of fiver; five-pound or five-dollar banknotes; people or things numbered five.
From 'five' (Old English 'fīf') plus '-er' (agent/object suffix) plus '-s' (plural), following the pattern 'liver,' 'giver,' 'fiver' (one worth five of something).
The word 'fiver' is brilliantly practical—speakers instantly created it to mean any note or coin worth five units of currency, so it works across dollars, pounds, euros, and pesos without needing new words.
Complete word intelligence in one call. Free tier — 50 lookups/day.