curl --request GET \
  --url http://localhost/api/v3/roles/definitions/{definition}

{
  "data": {
    "id": 123,
    "name": "<string>",
    "handle": "<string>",
    "description": "<string>",
    "short_description": "<string>",
    "icon": "<string>",
    "image_url": "<string>",
    "timezone": "<string>",
    "period": 123,
    "period_type": "<string>",
    "absolute_expiry": "<string>",
    "group_name": "<string>",
    "group_handle": "<string>",
    "notes": "<string>",
    "meta": [
      "<unknown>"
    ],
    "custom_fields": {},
    "created_at": "<string>",
    "updated_at": "<string>"
  }
}