hororo

The body is in the word. Latin horrere meant to bristle - of hair, of a field of corn, of a hedgehog. Horror was the shudder, the standing-up of the hairs, and only afterwards the emotion that causes it. That is a useful thing to know when choosing between the words for fear, because it tells you where hororo sits: it is the physical, involuntary, skin-level reaction, not the reasoned dread.

Against the rest of the fear vocabulary. Timo is fear in general and timi is to be afraid. Teruro is terror - large, overwhelming, the thing that makes you run. Hororo is revulsion mixed into the fear: the reaction to something not merely dangerous but wrong, a corpse rather than a cliff edge. Terura is the everyday adjective for terrible, and horora is its narrower cousin. If your sentence would take English appalling or grisly, horora is the one.

And the genre. Hororo is the standard Esperanto label for horror as a category of film and fiction: hororfilmo, hororromano, horora rakonto. Esperanto has a real if small tradition of it, mostly in translation, and the word behaves like any other genre name - la ĝenro de hororo, or just hororo used absolutely, the way English says he writes horror. Horori as a verb means to be horrified, and hororigi to horrify somebody else, which is the igi and iĝi pair doing exactly what it always does.