bored by the familiar, intrigued by novelty
A yojijukugo expressing the idea that one tires of the ordinary and is drawn to the new. The literal image is of a domestic chicken and a wild duck.
The phrase 家鶏野鶩 expresses the feeling of growing tired of the familiar and seeking novelty.
one's wife and one's mistress
A rare, extended figurative use contrasting the domestic (wife) with the wild (mistress).
In old texts, 家鶏野鶩 is sometimes used as a metaphor for one's wife and mistress.