"to listen" (especially with a stethoscope), 1832, from Latin auscultatus, past participle of auscultare "to listen attentively to," from aus-, from auris "ear" (see ear (n.1)); "the rest is doubtful" [OED]. Tucker suggests the second element is akin to clinere "to lean, bend."
aurochs
aurora
aurora borealis
auroral
*aus-
auscultate
auscultation
auspex
auspices
auspicious
Aussie