A "reclusive genius" refers to someone who is incredibly intelligent or talented but chooses to live a solitary or private life, away from social interactions or the public eye. Full definition
The movie follows a young programmer, Caleb (Domhnall Gleeson), chosen to spend a week in the remote boreal home and lab of his billionaire boss Nathan (Oscar Isaac), a reclusive genius who wrote the code for a Google - like search engine when he was a teen. (sciencenews.org)
Ray Jayawardhana: Indeed, and some very colorful characters that I write about in the book, including some physicists who you might not have heard of, like Ettore Majorana, an Italian physicist who was this reclusive genius, really struggled with many things in his life, and disappeared without a trace at age 32. (scientificamerican.com)
She's also a robot, pieced together by a reclusive genius in a house shrouded by mountains, and her thought processes are sparked by the terms millions of humans are keying into Blue Book, the world's most popular internet search engine. (telegraph.co.uk)