hibernaculum

American  

[hahy-ber-nak-yuh-luhm] / ˌhaɪ bərˈnæk yə ləm /

Also hibernacle

noun

plural

hibernacula

1. a protective case or covering, especially for winter, as of an animal or a plant bud.

2. winter quarters, as of a hibernating animal.

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hibernaculum British  

/ ˌhaɪbəˈnækjʊləm, ˈhaɪbəˌnækəl /

noun

1. the winter quarters of a hibernating animal

2. the protective case or covering of a plant bud or animal

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hibernaculum Scientific  

/ hī′-bər-năk′yə-ləm /

1. A protective case, covering, or structure, such as a plant bud, in which an organism remains dormant for the winter.

2. The shelter of a hibernating animal.

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Etymology

Origin of hibernaculum

First recorded in 1690–1700; from Latin hībernāculum “winter residence,” equivalent to hībernā(re) “to spend the winter” + -culum suffix denoting place

Explanation

If a cave is handy, a bear might choose it as its hibernaculum, a place to spend the winter while it's in a state of winter dormancy. A groundhog's hibernaculum is an elaborate underground burrow in which it spends the winter in a deep sleep. The word hibernaculum is borrowed from Latin, where it means "winter home." It's related to the English word hibernate, which is what some animals do to survive the harsh, winter months: They go into a deep, prolonged state of inactivity. A hibernaculum can be as simple as a hard, protective covering on an insect (or plant), or a pile of leaves to snuggle down in. While hibernaculum is a specific term in zoology and biology, it may be used figuratively to describe a person's winter retreat.

Example Sentences

Those offspring hibernate over winter as larvae - caterpillars - in a communal silken web called a hibernaculum.

From BBC • Nov. 30, 2025

He says human disturbance during hibernation can cause significant impacts to bats and may even result in the abandonment of the cave as a hibernaculum.

From Washington Times • Oct. 12, 2019

Construction of the winter cave, or hibernaculum, cost about $300,000.

From Washington Post • Oct. 29, 2012

It is the winter home, or hibernaculum, to 270,000 gray bats, listed as endangered partly because the entire species hibernates in only nine caves, three of those in Tennessee.

From New York Times • Sep. 24, 2012

They hatch in the same way as the others but when the caterpillars have moulted about twice they form a winter case or hibernaculum, in exactly the same way as the caterpillars of the Viceroy.

From Butterflies Worth Knowing by Weed, Clarence M.