aus- / Indo-European roots
Examples of words with the root aus-: aurora, austral, Austro-, east, Easter, eastern, eo-, Eos, eosin, ostmark, Ostrogoth.
▲ Derivatives include east, Easter, aurora.
a. east from Old English ēast, east (< "the direction of the sunrise");
b. ostmark from Old High German ōstan, east. Both a and b from Germanic *aust-.
a. eastern from Old English ēasterne, eastern;
b. Ostrogoth from Late Latin ostro-, eastern. Both a and b from Germanic *austra-.
3. Easter from Old English ēastre, Easter, from Germanic *austrōn-, dawn.
4. Possibly in Latin auster, the south wind, formally identical to the Germanic forms in 2 and 3, but the semantics are unclear austral, Austro-1
5. Probably suffixed form *ausōs-, dawn, also Indo-European goddess of the dawn.
a. aurora from Latin aurōra, dawn;
b. eo-, Eos; eosin from Greek ēōs, dawn.
[Pokorny au̯es- 86.]