What is the X in X-mas?
also shut-out, 1889 in baseball sense, from verbal phrase shut out "exclude from a situation" (late 14c.; from 1881 in the sports score sense), from shut (v.) + out (adv.). Middle English had a verb outshut "to shut out, exclude," mid-15c.
To stop talking; shut up • Often an irritated command (1899+)