This is the 6449th most frequent Russian word.
юг
South.
In this sentence, 'юг' refers to a general southern direction, in a migratory context.
Птицы отправляются на юг на зимовку.
Birds migrate south for the winter.
'Юг' is used to describe a specific geographical region within Russia.
На юге России климат мягче.
In the south of Russia, the climate is milder.
Here, 'юг' denotes a compass direction, specifically the southern part of a country.