Mick is a masculine given name or nickname, usually a short form (hypocorism) of Michael. Because of its popularity in Ireland, it is often used in England, the United Kingdom in general, English-speaking North America, and Australia as a derogatory term or ethnic slur for an Irish person or a person of Irish descent, particularly ethnic Irish Catholics. In Australia, the meaning also broadened to include any Roman Catholic. https://en.wikipedia.org/wiki/Mick