LXQt is a lightweight Desktop environment. Some LXDE developers decided to create a Qt based version of their Desktop environment, it's name was lxde-qt. Around the same time some other people were working on a different minimal Qt based DE called razor-qt. When some developers of those projects met they decided to join forces and work together on one project. LXQt was born.
It is recommended to set the LXQt mix-in before emerging it.
# eselect profile add funtoo/1.0/linux-gnu/mix-ins/lxqt # emerge lxqt-meta