The coldest season of the year; in the northern hemisphere it extends from the winter solstice to the vernal equinox WordNet 3.0

The coldest season of the year; in the Northern Hemisphere it extends from the winter solstice to the vernal equinox Open English WordNet

Winter is the coldest season of the year in polar and temperate climates. Wikipedia

One of the four temperate seasons. Wikipedia Disambiguation

A season Wikipedia Disambiguation

The coldest season of the year in temperate climates Wikipedia Disambiguation

Traditionally, the fourth of the seasons, marked by the applicable hemisphere of the planet being at its minimum angle of exposure to the Sun, resulting in short days, long nights and typically in low temperatures. OmegaWiki

Traditionally the fourth of the four seasons, typically regarded as being from December 23 to March 20 in continental regions of the Northern Hemisphere or the months of June, July and August in the Southern Hemisphere. It is the time when the sun is lowest in the sky, resulting in short days, and the time of year with the lowest atmospheric temperatures for the region. Wiktionary

The season of winter, between autumn and spring. Wiktionary

The season of winter. Wiktionary (translation)