oligarchical

UK: /ˌɒlɪˈgɑːkɪkəl/

WordReference Random House Learner's Dictionary of American English © 2025

ol•i•gar•chy /ˈɑlɪˌgɑrki/   n., pl. -chies. 

1. Government [uncountable] a form of government in which power is held by a few persons or by a dominant class or group.
2. Government a state or organization ruled this way:
   [countable] corrupt oligarchies.
3. Government the persons or class that rules this way:
   [countable] the ageing oligarchy.

ol•i•gar•chic, adj. See -arch-.

WordReference Random House Unabridged Dictionary of American English © 2025

ol•i•gar•chy  (ol′i gär′kē), n., pl. -chies. 

1. Government a form of government in which all power is vested in a few persons or in a dominant class or clique;
   government by the few.
2. Government a state or organization so ruled.
3. Government the persons or class so ruling.

• Greek oligarchía. See olig-, -archy
• Medieval Latin oligarchia
• 1570–80

Collins Concise English Dictionary © HarperCollins Publishers::

oligarchy / ˈɒlɪˌɡɑːkɪ/ noun ( -chies)

1. government by a small group of people
2. a state or organization so governed
3. a small body of individuals ruling such a state
4. a small clique of private citizens who exert a strong influence on government

Etymology: 16th Century: via Medieval Latin from Greek oligarkhia, from olígos few + -archy

ˌoliˈgarchic, ˌoliˈgarchical, ˌoliˈgarchal adjective