Other forms: geniuses, genii
A genius is somebody with an exceptionally brilliant mind. A mathematical genius, a stroke of genius, she is a genius.
It is used both for the person and for the quality: he has genius, which is uncountable, and he is a genius, which is countable. The word is thrown about loosely in praise, and the strict sense — once-in-a-generation ability — is worth keeping in mind. The plural is geniuses; genii belongs to the older sense of a guardian spirit. Note the genius of a place or a language, meaning its distinctive character, which is formal and rather beautiful.
1noungeniusSomebody with exceptional ability.
“He was a genius and impossible to work with.”
2nounitselfExceptional ability itself.
“There is genius in the arrangement and none in the tune.”
3noundistinctiveThe distinctive character of a place, time or language.
“It runs against the whole genius of the language.”
Too few real examples of this word to estimate which sense is commonest.
genius is exceptional ability.
Latin genius meant the guardian spirit attached to a person from birth, from a root meaning to be born — the same root as genus, generate and gene. Your genius was originally something you had rather than something you were, and the modern sense is that spirit's gifts credited to the person.
Proto-Indo-European
*ǵenh₁-
itc-ola
genō
Latin
genius — inborn nature; a tutelary deity of a person or place; wit, brilliance
English, today
genius
Built from
From Latin genius (“inborn nature; a tutelary deity of a person or place; wit, brilliance”), from gignō (“to beget, produce”), itc-ola genō, from the Proto-Indo-European - root ǵenh₁-. a doublet of genio. See also genus and genie.
Etymology from Wiktionary, CC BY-SA