Eurus Holmes: I’m Eurus.

John Watson: Eurus?

Eurus Holmes: Silly name, isn’t it? Greek. Means “the east wind”. My parents loved silly names, like Eurus… or Mycroft… or Sherlock. Oh, look at him. Didn’t it ever occur to you, not even once, that Sherlock’s secret brother might just be Sherlock’s secret sister? Huh? He’s making a funny face. I think I’ll put a hole in it.

From Sherlock – Season 4 Episode 2: ‘The Lying Detective’ (4×02)