Who is you guys? You can be one of "those guys" by submitting a change to JMDict, the database that Jisho uses. The people who made Jisho don't write the dictionary entries.
All of the Wikipedia entry things are just automatically scraped. I'm not too sure what the complaint is about that.
Googling for "virtuosity 意味" brings up results for 妙技 and 名人芸. These are on Jisho, but don't use that specific word.
名人芸 looks useful. Would you use this word to describe the way the Yoshida Brothers play? Yo-yo Ma?
A monolingual definition of 名人芸 is
十分な修業を積んだ名人にしかできないような高度な技芸。
A high level of artistic ability that can only be achieved by a master who has sufficiently trained.
I don't know much about those performers, but if that sounds appropriate to you, then it's an option.
thank you Leebo. Now can you please tell me how I can fix it so that a search for English "virtuosity" will bring up 「名人芸」？
If you go to the entry for 名人芸, you'll see a thing you can click on the left that says "Links". If you click it, the bottom option should be "edit in JMdict." You can then propose an update to JMdict, and if it's accepted, it would propagate Jisho and all resources that use JMdict.
バーチュオシティ = "virtuosity" ???
c'mon, guys, you can do better than this! How do you say "an extreme level of technical skill"?