An abattoir is a slaughterhouse, or a place where animals are killed. It's not a word you're likely to hear or use unless you're involved in these activities.

However, break abattoir into its component parts, abate + -ory, and things get a lot more interesting. -Ory is simple: it means "a place for," as in factory, laboratory, and even auditorium. Abate is more complex. Today it means "to lessen," but back when it came to English via the Old French abattre, it meant "to beat down," a meaning Old French had inherited from the Latin ad ("to") + battere ("beat"). So when you think of abattoir, you can think of the idea of "a beating," or an animal's life "abating" until it is gone.

Definitions of abattoir

n a building where animals are butchered

butchery, shambles, slaughterhouse
Type of:
building, edifice
a structure that has a roof and walls and stands more or less permanently in one place