Reappropriation

Reappropriation, or Amelioration, is the reclaiming of linguistic terms with histories of nasty usage as a way to help create a sense of pride and or/power. The canonical examples are "nigger" and "queer". It has also happened historically; the terms "American" (for a continental), "Tory" (for a UK Conservative), and "Whig" (for a UK liberal) all used to be derogatory slurs thrown at them by others. If only someone told the US's modern liberals...

The goal is to use the word enough in a communal setting so as to weaken its hateful roots, and eventually turn it into a friendly term. Though in most cases where this has been done, it's only acceptable for the group being tarred by that word to use it. Indeed, according to Chris Rock, there is only one highly convoluted situation when it's appropriate for a white person to say "nigger".

In partisan US politics
More recently, the word seems to have been given a new meaning by cranks, who throw around with wild abandon the notion that politicians could reappropriate funds from discretionary government spending in order to pay for whatever insane idea they have come up with. If pressed, they tell you they will explain it later, or it's too technical, but there is plenty of that funding out there.

Extreme wingnut reappropriation
In 2012, Bryan Fischer launched a campaign to reappropriate the word "discrimination", which to most ordinary people would sound like trying to "reappropriate" words such as "evil", "cruelty", or "excruciating pain". Said Fischer: "Bottom line: it’s time for conservatives to unhesitatingly reclaim the “D” word, dust it off, and use it without apology." (Fischer's expressed target was discrimination against — what else? — homosexuals, but people like Fischer would surely find plenty of other potential applications as well.)