also: だいにのふるさと
expression, noun
second home; home away from home
Refers to a place where one feels as comfortable and attached as in one's hometown, often used for a city or country where one has lived for a long time.
長年住んだこの街は、私にとって第二の故郷です。
This city where I've lived for many years is my second home.
留学先の国が第二の故郷になった。
The country where I studied abroad became my home away from home.
故郷 means 'hometown' or 'birthplace'; 第二の故郷 extends this to a place that feels like a second hometown.
A set phrase composed of 第二 (second) + の (possessive particle) + 故郷 (hometown). The expression is a direct calque of the English 'second home' or 'home away from home'.