With more than 5.5 million articles, Wikipedia is an invaluable resource, whether you’re throwing a term paper together at the last minute or trying to find that 15-minute window when a pear is neither rock-hard nor complete mush. We explore some of Wikipedia’s oddities in our 5,502,304-week series, Wiki Wormhole.

This week’s entry: Giallo

What it’s about: America had pulp novels; Italy had giallo. The word for “yellow,” giallo refers to a series of paperback mystery novels published in the ’50s with bright yellow covers. The name was used again for the wave of horror films first produced in the ’60s, and for Italian horror ever since. (The books were mostly repackaged Agatha Christie, Raymond Chandler, and the like, but the films were original and sometimes termed “spaghetti thrillers,” à la spaghetti Westerns.