genius

1 ENTRIES FOUND:
genius /ˈʤiːnjəs/ noun
plural geniuses
genius
/ˈʤiːnjəs/
noun
plural geniuses
Britannica Dictionary definition of GENIUS
1 
[count]
a  : a very smart or talented person : a person who has a level of talent or intelligence that is very rare or remarkable
b  : a person who is very good at doing something
2 
a  [noncount] : great natural ability : remarkable talent or intelligence
b  [singular] : a great or unusual talent or ability — usually + for
3 
[singular]
a  : a very clever or smart quality
b  : a part of something that makes it unusually good or valuable

a stroke of genius

: a brilliant and successful idea or decision