cleanskin
noun
1
a person without a criminal record. Originally applied to an unbranded sheep AUSTRALIA, 1943.
2
a novice. From the conventional sense (an unbranded stock animal) AUSTRALIA, 1907.
3
a person of integrity, especially in a political context. From the sense of 'a person without a police record' AUSTRALIA, 1942.
4
in horse racing, a jockey who has never been disqualified in a race AUSTRALIA, 1989