Main Entry:

¹ter·tia·ry

Pronunciation:

\ˈtər-shē-ˌer-ē, -shə-rē\

Function:

noun

Inflected Form(s):

plural ter·tia·ries

Date:

circa 1550

1 [Medieval Latin tertiarius, from Latin, of a third] : a member of a monastic third order especially of lay people2capitalized : the Tertiary period or system of rocks