Austral \Aus"tral\, a. (Biogeography) Designating, or pert. to, a zone extending across North America between the Transition and Tropical zones, and including most of the United States and central Mexico except the mountainous parts.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Austral \Aus"tral\, a. [L. australis, fr. auster: cf. F. austral.]

Southern; lying or being in the south; as, austral land; austral ocean.

Austral signs (Astron.), the last six signs of the zodiac, or those south of the equator.

Source: Webster's Revised Unabridged Dictionary (1913)