"a state of limited competition in which a market is shared by a few producers or sellers," 1887, from Medieval Latin oligopolium, from Greek oligos "little, small," in plural, "the few" (a word of uncertain origin) + pōlein "to sell" (from PIE root *pel- (4) "to sell."). Related: Oligopolist.
oligarchic
oligarchy
oligo-
Oligocene
oligopolistic
oligopoly
oligotrophy
oliguria
olio
oliphant
olive