Spine-chilling describes something that frightens you in a slow, creeping way — the cold-down-the-back kind of fear, not the jump-out-of-your-seat kind. A spine-chilling ghost story, a spine-chilling scream heard through a wall, a spine-chilling silence just before something happens.

It is an adjective, and it sits both before a noun ('a spine-chilling film') and after 'be' ('the last scene was spine-chilling'). It comes from the way fear actually feels in the body: cold running down the spine. English builds several words this way — blood-curdling, hair-raising, bone-chilling — all of them describing the fright by describing what your body does.

Two things about its real use. First, the dictionary line says a spine-chilling story or film 'is very frightening in a way that people enjoy', and that is true for stories — you paid for the ticket, you wanted to be scared. But the word is not locked inside fiction. Newspapers use it for real things too, and then all the enjoyment drops away: 'a spine-chilling recording of the call', 'spine-chilling evidence'. Context tells you which one you are getting.

Second, it has a slightly heightened, written flavour — reviews, blurbs, headlines. Talking to a friend, most people just say 'really scary' or 'so creepy'. Using spine-chilling in casual speech is not wrong; it is just a size larger than the moment usually needs.