Yugoslavia (a former country in Southeastern Europe in the Balkans, now split into 6 countries: Bosnia and Herzegovina, Croatia, North Macedonia, Montenegro, Serbia, and Slovenia)
a right tributary of the Cher in the department of Cher, Centre-Val de Loire, France; a right tributary of the Auve in the department of Marne, Grand Est, France
to fly by the seat of one's pants, to play by ear, to wing it (to sit an exam without having studied for it, relying only on one's skills and previous knowledge)