krepusko

One of the better words the language borrowed, and it earns its place. Krepusko is the light that is neither day nor night: the half hour after the sun has gone and before the dark closes, and equally the same light before dawn. Esperanto is precise where English hedges - matena krepusko is first light, vespera krepusko is dusk, and the plain krepusko on its own is understood as the evening one unless you say otherwise.

It is not vespero. Vespero is the evening as a block of time, hours long, and it can be brightly lit and indoors. Krepusko is a quality of light and it lasts minutes. That is why it is the word a story reaches for when it wants the fire to be lit and the first stelo to come out.

The family is small and useful. Krepuska is the adjective, and krepuski is a real if rare verb meaning for the light to be doing this. Latin's crepusculum carried a -culum diminutive, so what the Romans literally said was "a little darkness" - which is a better description than either English word manages.