http://repoforge.org/use/

The RepoForge project offers RPM packages not available in the official repos.

Check for proper version first (64-bit shown here)

rpm -Uhv http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm

Disable the repository unless specifically enabled:

vim /etc/yum.repos.d/rpmforge.repo

enabled=0

Use the repo like this:

yum install --enablerepo=rpmforge <package-name>