The Collaborative International Dictionary
Tribual
Tribual \Trib"u*al\, Tribular \Trib"u*lar\, a. Of or relating to a tribe; tribal; as, a tribual characteristic; tribular worship. [R.]
The tribual lispings of the Ephraimites.
--Fuller.
Wiktionary
tribual
a. of, or relating to a tribe; tribal