define estivation
Princeton's WordNet(4.00 / 1 vote)Rate this definition: 1  estivation, aestivation(noun) (zoology) cessation or slowing of activity during the summer; especially slowing of metabolism in some animals during a hot or dry period. 2  estivation, aestivation(noun) (botany) the arrangement of sepals and petals in a flower bud before it opens.