夏: summer

夏 xià

noun
: summer
: the Xia or Hsia dynasty c. 2000 BC; Xia of the Sixteen Kingdoms (407-432);

Kun Reading

夏 | なつ natsu

adverbial noun | temporal noun
: summer

夏い | なつい natsui

adjective | colloquialism
: blisteringly hot; relentlessly hot; scorching

四季 si4ji4: four seasons

春 chun1: spring
夏 xia4: summer
秋 qiu1: autumn
冬 dong1: winter

夏天 xia4tian1: summer

夏季 xia4ji4: summer [かき kaki OR なつき natsuki: summer season]

夏代 xia4dai4: Xia or Hsia dynasty c. 2000 BC

夏令 xia4ling4: summer; summer weather

夏令營[营] xia4ling4 ying2: summer camp

仲夏 zhong4xia4: midsummer; second month of summer [ちゅうか chuuka: midsummer]

冬夏 dong1xia4: winter and summer

初夏 chu1xia4: early summer [しょか shoka OR はつなつ hatsunatsu: early summer]

夏威夷 xia4 wei1 yi2: Hawaii

冬蟲夏草 [冬虫夏草] dong1 chong2 xia4 cao3: caterpillar fungus (Cordyceps sinensis) [highly prized herbal medicine]

Natsume’s Book of Friends (夏目友人帳 Natsume Yūjin-chō) is a supernatural, fantasy manga series by Yuki Midorikawa. It began serialization in 2005 and is ongoing. The series has been adapted to drama CDs and 5 seasons of anime series (2008, 2009, 2011, 2012, and the fifth season is scheduled for fall 2016).

The series is about Natsume Takashi, an orphaned teenage boy who can see spirits, who inherits from his grandmother, Reiko, the notebook she used to bind spirits under her control. Because the notebook, Book of Friends, is highly sought after in the spirit world, Natsume is constantly haunted by other spirits looking to gain control of the book. One such spirit is Madara (Nyanko-sensei by Natsume), an overweight cat, who serves as Natsume’s bodyguard in return to eventually inherit the book from Natsume.
— wikipedia
photo credit: hummingbird forum

Japanese common word | expression | yojijukugo 四字熟語 | idiom
夏休み | なつやすみ natsu yasumi: summer vacation; summer holiday
[暑假 shu3jia4: summer vacation]

*春夏秋冬 | しゅんかしゅうとう shunka shuutou
: (yoji) spring, summer, autumn (fall) and winter; the four seasons

夏炉冬扇 | かろとうせん karo tousen
: (yoji) summer fires and winter fans; useless things

飛んで火に入る夏の虫 | とんでひにいるなつのむし tonde hi ni iru natsu no mushi
: rushing to one’s doom; (like a) moth flying into the flame

Chinese expression | chengyu 成語 | idiom
*春夏秋冬 chun1 xia4 qiu1 dong1
: the four seasons; spring, summer, autumn and winter

無冬無夏 [无冬无夏] wu2 dong1 wu2 xia4
: regardless of the season; all the year round

夏蟲不可以語冰 [夏虫不可以语冰] xia4 chong2 bu4 ke3 yi3 yu3 bing1
: A summer insect (which does not live to see winter) cannot talk about ice; to have limited experience and knowledge

春生，夏長，秋收，冬藏 [春生，夏长，秋收，冬藏] chun1 sheng1 , xia4 zhang3 , qiu1 shou1 , dong1 cang2
: sow in spring, develop in summer, harvest in autumn, store in winter