fra·ter·nal 
(frə-tûrnəl)
(frə-tûrnəl)adj.
1.
a. Of or relating to brothers: a close fraternal tie.
b. Showing comradeship; brotherly.
2.
a. Of or constituting a fraternity: a fraternal association.
b. Roman Catholic Church Of or constituting a mendicant order such as the Dominicans or Franciscans.
3. 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 the Appendix of Indo-European roots.]
fra·ternal·ism n.
fra·ternal·ly adv.