1. A place which serves as protection, or shelter, in very cold months of the year: They are the winter refuges; such as, the hibernacle of an animal or a plant.
2. In botany, the winter quarters of a plant: A bulb or a bud in which the embryo of a future plant is in a hibernacle or it is in an enclosed scaly covering that protects it from damage during the very chilly time during fall, winter and spring.