- a person with two distinct personalities, one good, the other evil
- (as modifier): a Jekyll-and-Hyde personality
WordReference Random House Unabridged Dictionary of American English © 2020
Jek′yll and Hyde′ ( jek′əl, jē′kəl),USA pronunciation
a person marked by dual personality, one aspect of which is good and the other bad.
- after the protagonist of Robert Louis Stevenson's The Strange Case of Dr. Jekyll and Mr. Hyde (1886)
Collins Concise English Dictionary © HarperCollins Publishers::
Jekyll and Hyde /ˈdʒɛkəl; haɪd/ n