jackanapes

UK: /ˈdʒækəˌneɪps/ US: ( jak′ə nāps′)

WordReference Random House Unabridged Dictionary of American English © 2025

jack•a•napes  ( jak′ə nāps′), n. 

1. an impertinent, presumptuous person, esp. a young man;
   whippersnapper.
2. an impudent, mischievous child.
3. [Archaic.] an ape or monkey.

• late Middle English Jakken-apes, literally, jack (i.e., man) of the ape, nickname of William de la Pole (1396–1450), Duke of Suffolk, whose badge was an ape's clog and chain 1400–50

Collins Concise English Dictionary © HarperCollins Publishers::

jackanapes / ˈdʒækəˌneɪps/ noun

1. a conceited impertinent person
2. a mischievous child
3. a monkey

Etymology: 16th Century: variant of Jakken-apes, literally: Jack of the ape, nickname of William de la Pole (1396–1450), first Duke of Suffolk, whose badge showed an ape's ball and chain