Of or relating to brothers: a close fraternal tie.
Showing comradeship; brotherly.
Of or constituting a fraternity: a fraternal association.
Biology Of, relating to, or being a twin developed from two separately fertilized ova; dizygotic.
[Middle English, from Old French fraternel, from Medieval Latin frāternālis, from Latin frāternus, from frāter, brother; see bhrāter- in Indo-European roots.] fra·ter'nal·ism n., fra·ter'nal·ly adv.