v. 1 close, fasten, secure, shut up; lock, bolt, seal Come in and shut the door 2 shut down. close down, discontinue, cease, suspend, halt, leave off, shut up; switch or turn or shut off, stop We shut down operations at the Enfield factory last week Make sure you shut down the machinery before leaving. 3 shut in. a confine, seclude, keep in, pen, fence in, secure We shut the dog in before we went out b See 6, (a), below. 4 shut off. a switch or turn off, shut down, Colloq kill, douse, cut (off) They shut off the lights while I was shaving b separate, isolate, seclude, segregate, sequester, bar, shut out, cut off, send to Coventry The more violent cases are shut off in another wing c close (off), shut (down) To save on heating, we shut off part of the house in the winter 5 shut out. a exclude, eliminate, bar, debar, lock out, ban, keep out or away, disallow, prohibit Aliens without work permits are shut out from employment We shut out all hooligans and rowdies. b keep out, screen, exclude, block out, cut out This window shade shuts out the direct sunlight c screen, mask, hide, conceal, veil, cover The house is shut out from view by the hedge 6 shut up. a confine, shut in, coop (up), cage (in), bottle up, box in; imprison, jail, incarcerate, intern, immure People suspected of being subversives were shut up during the war b silence, keep quiet, stifle, mute, gag, shush, Chiefly Brit quieten As soon as Colin wants to say something, Sidonie shuts him up c See 1, above. d See 2, above.
adj. 7 closed (up), sealed (up), locked (up), bolted, fastened There is not much hope of penetrating their shut minds on this issue