quark [M20th] In physics a quark is a type of subatomic particle believed to be one of the basic constituents of matter. The name was coined in the 1960s by the American physicist Murray Gell-Mann, who initially spelt it quork but changed this to quark after he came across the line ‘Three quarks for Muster Mark’ in James Joyce’s Finnegans Wake (1939). Joyce’s word is meant to suggest the cawing sound seagulls make. It appealed to Gell-Mann, as at the time only three varieties of quark (known as up, down, and strange quarks) were believed to exist.