(ˈtɜːʃəl) adj, n (Zoology) another word for tertiary5, tertiary6[C19: from Latin tertius third, from ter thrice, from trēs three]
ter•tial
(ˈtɜr ʃəl)
adj. 1. pertaining to any of a set of flight feathers situated on the basal segment of a bird's wing. n. 2. a tertial feather. [1830–40; < Latin terti(us) third + -al1]EncyclopediaSeetertiaryThesaurusSeeTertiary