Fr.: hiver par impact
The enormous drop in temperature and the related effects of the shrouding of Earth with soot and dust particles after the planet is struck by a sizable comet or asteroid. Such a phenomenon is believed to have killed off the dinosaurs 65 million years ago.
The season beginning at the → winter solstice, about December 22 and lasting until the → vernal equinox, about March 21.
M.E., OE; cf. O.Fris., Du. winter, O.S., O.H.G. wintar, Ger. winter, Dan., Swed. vinter, Goth. wintrus "winter"),
Zemestân "winter," related to zam "cold," Mid.Pers. zam, zamistân "winter;" Av. zimô "winter;" cf. Skt. hima- "cold, frost;" Ossetic zymæg/zumæg "winter;" Gk. xeimon "winter;" L. hiems "winter;" Lith. ziema "winter;" PIE *gheim- "snow, winter."
Fr.: solstice d'hiver
The moment in the northern hemisphere when the → Sun attains its lowest → declination of -23°26' (or -23°.44) with respect the → equator plane. It happens when the Earth's axis is orientated directly away from the Sun, on 21 or 22 December. During the northern winter solstice the Sun appears to be directly overhead at noon for places situated at → latitude 23.44 degrees south, known as the → tropic of Capricorn. The winter solstice can occur at any moment during the day. Two successive winter solstices are shifted in time by about 6 h. The winter solstice in the northern hemisphere is the → summer solstice in the southern hemisphere.