Sometimes, I wonder about how anime get their names. Honestly, I could probably do a whole series of cards on the subject because while some anime are very straight forward in the title (i.e. Fairy Tail), others are not so clear (D. Gray Man).
Today, let's talk about Haikyuu!!I
I did some googling, and I found this AWESOME answer about what the name really means:
As a title, "Haikyuu!!" actually makes for a pretty interesting look into how Japanese works. You may already know that written Japanese descended from written Chinese. Over time, the Japanese people adapted the Chinese script to fit their spoken language. This resulted in three separate writing systems: Kanji, the Chinese characters that survived the evolution of the Japanese language up to modern times. These characters denote whole words or concepts and are identical to their Chinese counterparts. Hiragana, the syllabic characters that represent all the sounds that exist natively in Japanese. Native Japanese words without a kanji representation are almost always written in hiragana, and kanji characters can be (and frequently are!) written in hiragana. Katakana, the syllabic characters that represent Japanese and non-Japanese sounds. Katakana are most frequently used to spell foreign loan words and company names, but are also sometimes used in place of hiragana for stylistic purposes. So, back to "Haikyuu!!" In Chinese, "volleyball" is written as 排球 In Japanese, this can be written in hiragana as はいきゅう (pronounced "haikyū") which you'll recognize as the name of our favorite volleyball-oriented anime. However, in modern Japanese, volleyball is called by a Japanese-sounding approximation of its English name. Because it's a foreign loan word, it is written in katakana: バレーボール (pronounced "barēbōru") Because this has become the standard Japanese word for "volleyball," the kanji representation and its hiragana spelling are basically obsolete. For this reason, the author of "Haikyuu!!" decided to use the old, native word as the manga's title, but written in katakana instead of the typical hiragana: ハイキュウ (pronounced "haikyū") making for a kind of pun.
The simple answer, though, is that the title "Haikyuu!!" just means "Volleyball!!"
Who woulda thunk it? :P