From Gentoo Wiki
Epiphany, sometimes called simply web, is a simple, fast Webkit-based web browser built for GNOME and Pantheon. It's main goal is to create a web browser that is free, open source, aesthetically pleasing and clean. It comes with a built-in adblocker and Intelligent Tracking Prevention by default.
USE flags for www-client/epiphany GNOME webbrowser based on Webkit
||Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)|
emerge --ask www-client/epiphany
Epiphany also offers a flatpak version. It is the recommended way of installing epiphany by the developers.
emerge --ask sys-apps/flatpak
Install epiphany from flathub.
flatpak install flathub org.gnome.Epiphany
Run through the command line:
flatpak run org.gnome.Epiphany
See Flatpak for more information.