Caliginous is an adjective that means ‘obscure’ or ‘murky.’

Coming to English in the mid-16th century, our word of the day originated in Latin, where it means ‘misty.’ In recent years, its meaning has broadened to also mean ‘dim’ or ‘obscure.’

For example: The caliginous sky didn’t make for the most ideal conditions, but it certainly looked cool. That murky look would be a perfect opening for a vampire movie.