tertial

Of the third rank or row among the flight-feathers of a bird's wing; tertiary, as a quill-feather.

A tertiary flight-feather; one of the pennæ, or large feathers, of a bird's wing of the third set, which grow on the elbow or upper arm; one of the tertiaries.

Same as tertiary.

Any flight feather attached to the humerus (upper arm) of a bird.