How to install new TTF, OTF or TTC fonts on a Linux system
Any TTF, OTF, or TTC (TrueType Collection) files can be manually installed on an ad hoc basis.
Gnome way
Opening a Nautilus window to fonts://
and dragging and dropping.
Command line
Copy a font file in the directory /usr/local/share/fonts
(for all users) or ~/.fonts
(for a specific user).