fossa

1 of 2

noun (1)

fos·​sa ˈfä-sə 

plural fossae ˈfä-ˌsē  -ˌsī 

: an anatomical pit, groove, or depression

fossa

2 of 2

noun (2)

fos·​sa ˈfä-sə 

: a slender, long-tailed, carnivorous mammal (Cryptoprocta ferox of the family Eupleridae) of Madagascar that has retractile claws, usually reddish-brown or sometimes black, short, thick fur, and anal scent glands

The fossa evolved on the catless island of Madagascar, where it became the ecological equivalent of a cat. With nothing else around to fill the role, the fossa became a sort of mini-leopard, hunting lemurs and other small animals in the forest at night.

—Fiona Sunquist

Illustration of fossa

• ²fossa

Examples of fossa in a Sentence

Recent Examples on the Web

Noun

After meeting a female fossa named Shala, the pair successfully produced four pups, marking a significant achievement for the European breeding program. —Real-Time News Team, Miami Herald, 17 Oct. 2025

Acheron Fossae is filled with dramatic landscape features — most notably, its namesake fossae, or fault-like channels that criss-cross the surface. —Stefanie Waldek, Space.com, 11 Aug. 2025

Similar to a golf ball resting on a golf tee, only a small portion of the humeral head makes contact with the glenoid fossa at any time. —Tim Petrie, Dpt, Verywell Health, 28 July 2024

In life, the carnivore was about the size of a bobcat and probably behaved like a civet or fossa. —Riley Black, Smithsonian Magazine, 29 June 2023

Word History

Etymology

Noun (1)

borrowed from Medieval Latin, going back to Latin, "ditch, trench," noun derivative from feminine of fossus, past participle of fodere "to jab, dig" — more at fossil entry 1

Noun (2)

borrowed from French, borrowed from Malagasy fosa

First Known Use

Noun (1)

1733, in the meaning defined above

Noun (2)

1838, in the meaning defined above

Rhymes for fossa

• casa
• masa
• ossa
• manasseh

Kids Definition

fossa

noun

fos·​sa

ˈfäs-ə

: a slender long-tailed meat-eating mammal of Madagascar that has usually reddish brown short thick fur and is an excellent climber

Medical Definition

fossa

noun

fos·​sa ˈfäs-ə 

plural fossae -ˌē  -ˌī 

: an anatomical pit, groove, or depression

the temporal fossa of the skull

the fossa in the liver for the gallbladder

fossate

-ˌāt 

adjective