anything or anyone closely related to or resembling another:
The film producer tried not to make the movie a first cousin to his last hit.
Origin
1965-70
Examples from the web for first cousin
Parody would be a first cousin, a satire on an actual work of art.
It is sweetish and gloppy and a first cousin of dog food.
One of the new board members was the respondent's first cousin.
Idioms and Phrases with first cousin
first cousin
A close relation or resemblance to someone or something, as in This new machine is a first cousin to the previous model. The figurative use of cousin, which literally means “the child of one's aunt or uncle,” dates from the 1300s.