tertiary

Beſides theſe primordial mountains, M. w:Peter Simon Pallas Pallas]] maintains, that there are others of a more recent origin. These he calls ſecondary and tertiary: […] the latter ariſe from the wrecks and contents of the ſea, raiſed and tranſported by volcanic eruptions and conſequent inundations.

a tertiary alcohol, amine, or salt

The primary, secondary, and tertiary wing feathers (remiges) of adult mourning doves are shed and replaced yearly in an orderly sequence, so flight is possible during molt. […] Little is known about the shedding sequence of the secondary or tertiary feathers or the related coverts. If it is similar to that of passerines, however, loss of the outermost tertiary feather occurs coincident with loss of the fifth or sixth primary[…]. The molt then would continue sequentially until the last or innermost tertiary was shed and replaced.