This is a Sanskrit word. The Sanskrit meaning of "Gruha" is house. And the word Grihastha symbolises a person who runs a house.
Usage
This word is generally used to denote a particular phase of life( next 40 years {20-60 years of human life span} after Brahmacharya ). This is the phase of life in which a man gets married and settles down in life and begets children. It is the second in the four phases of a man, namely, Brahmacharya, Grihastha, Vanaprastha , and finally Sanyasa, as prescribed by Manusmriti for the Dhwija castes, in the Hindu system of life.