Proper noun
Fimbulwinter
English Wikipedia has an article on:FimbulwinterWikipedia
(Norse mythology) One of the signs of the onset of the end of this world, the final, three-year-long winter (with no intervening summers); it marks the coming of the Ragnarok, the battle that will end the world.
Fimbulwinter is three successive winters, when snow comes in from all directions, without any intervening summer. Source: Internet