(US, idiomatic) A repeat expatriate, one who becomes ex-patriated a second time.
Example: 2004. Alan Levy, in the film Rex-patriates, and quoted by The Prague Post: What's a Rex-pat:
A rex-pat is a returning expatriate, an ex-pat has been here, goes home to America, takes a job, maybe goes to law school, maybe does well in America but can't get Prague out of his or her blood and returns to Prague to live again.
ca2007. Phylis Gardner The Prague Post: What's a Rex-pat:
Well what Levy calls rex-pats are nothing more than expats who went home and simply couldn't make it. The failures in question return to Prague because the city allows them to live in a sort of perpetual adolescence. In my research I've discovered that something like 28% of all Prague ex-pats who leave the city return within two years, a terrifying statistic.