The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
ors-
DEFINITION:
Buttocks, backside. 1. Suffixed form *ors-o-.a.ass2, from Old English ærs,ears, backside; b.dodo, from Middle Dutch ærs, backside, tail. Both a and b from Germanic *arsaz.2. Suffixed form *ors--.a. uro-2, –urous; anthurium, anuran, cynosure, dasyure, eremurus, ophiuroid, oxyuriasis, sciurid, squirrel, trichuriasis, from Greek our, tail; b.silurid, from Greek silouros, sheatfish, probably from our, tail (with an obscure first element). (Pokorny ers- 340.)
-. a. uro-2, –urous; anthurium, anuran, cynosure, dasyure, eremurus, ophiuroid, oxyuriasis, sciurid, squirrel, trichuriasis, from Greek our
