越冬[ettou] passing the winter
夏炉冬扇[karotousen] summer fires and winter fans
旧冬[kyuutou] former winters
厳冬[gentou] severe winter
今冬[kontou] this winter

三冬[santou] three winter months
春夏秋冬[shunkashuutou] spring, summer, autumn (fall) and winter
初冬[shotou] early winter
真冬[mafuyu] midwinter
暖冬[dantou] mild winter

夏至[geshi] summer solstice
夏至線[geshisen] Tropic of Cancer
夏至点[geshiten] summer solstitial point
至って[itatte] very much
至らない[itaranai] imperfect

至る[itaru] to arrive at (e.g. a decision)
至る処[itarutokoro] everywhere
至れりつくせり[itareritsukuseri] very polite
至急[shikyuu] urgent
至急便[shikyuubin] express mail