/<instance_id>/synonyms/{synonym_id}/enable - POST

{
    "type": "catalog",
    "lang": "en",
    "enabled": true,
    "synonyms": [
        "yellow"
    ],
    "alternatives": [
        "lemon",
        "banana"
    ],
    "extra": {
        "user": "username"
    },
    "batched": false,
    "id": "586c267572c547cdcb51be9c"
    "created_on": "2017-01-03T22:32:21"
    "updated_on": "2017-01-03T22:32:21"
}

{
  "code": 401,
  "details": "The server could not verify that you are authorized to access the URL requested.  You either supplied the wrong credentials (e.g. a bad password), or your browser doesn't understand how to supply the credentials required.",
  "message": "Unauthorized",
  "status": "error"
}

{
  "code": 404,
  "details": "Invalid id '123456'",
  "message": "Not Found",
  "status": "error"
}