idiot sa·vant
| \ ˈē-ˌdyō-sä-ˈväⁿ
or same as idiot and savant for respective singular and plural forms\
plural idiots savants\ ˈē-ˌdyō-sä-ˈväⁿ(z)
\
or idiot savants\ ˈē-ˌdyō-sä-ˈväⁿ(z)
\
2
: a person who is highly knowledgeable about one subject but knows little about anything else