Update src/appendix/glossary.md
Update src/appendix/glossary.md

Co-authored-by: Who? Me?! <c15a8b12f9f792dbc50834ec1cf7e22bcc3105c7@users.noreply.github.com>
rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide