es·​ti·​va·​tion | \ ˌe-stə-ˈvā-shən How to pronounce estivation (audio) \
variants: or aestivation

Definition of estivation

1 zoology : the state or condition of torpidity or dormancy induced by the heat and dryness of summer : the state of one that is estivating Some animals, including various species of snakes, land snails, and lizards, enter a state of dormancy, or estivation, in the summer when water is scarce.— Carrol B. Fleming … they [land snails of the genus Cerion] spend most of this time in the warm weather equivalent of hibernation (called estivation), hanging upside down from vegetation or affixed to rocks.— Stephen Jay Gould
2 usually aestivation, botany : the arrangement or position of the petals or sepals in a flower bud In practice, aestivation is best observed by making hand sections of mature flower buds …— Michael G. Simpson … flowers on the same plants or the same stem may exhibit either clockwise or counterclockwise spiral estivations— Carlos Herrera — compare vernation

First Known Use of estivation

1783, in the meaning defined at sense 1

Keep scrolling for more

Learn More about estivation

Time Traveler for estivation

Time Traveler

The first known use of estivation was in 1783

See more words from the same year

Statistics for estivation

Cite this Entry

“Estivation.” Dictionary, Merriam-Webster, Accessed 10 Jul. 2020.

Keep scrolling for more

More Definitions for estivation


variants: or aestivation \ ˌes-​tə-​ˈvā-​shən How to pronounce aestivation (audio) \

Medical Definition of estivation

: the state of one that estivates

More from Merriam-Webster on estivation Encyclopedia article about estivation

Comments on estivation

What made you want to look up estivation? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!