Within a successful, seemingly stable relationship, the settler refers to the "better half", who in essence settles with their partner. This person tends to be either more attractive, wealthier, smarter, personable or some other quality that would seemingly make their partner look inferior, to the extent that people begin to question why they would even date in the first place.
The opposite of a reacher
Looking at the Janet Jackson and Jermaine Dupri relationship, it is painfully clear that Janet (Ms. Jackson, if you're nasty) is a settler.
Not quite a gold digger or a 49er, a copper settler stays or "settles" with another individual, not for their looks nor moderate wealth (thus why copper, and not gold), but to live a menial lifestyle for the rest of their lives
When a woman in her mid thirties who settles for a cheap, average, boring guy who might be gay. But he's 30 and a pediatrician! What can gowrong!? She must be a copper settler!