Demo asked in a comment what yakyu was, and rather than reply in a comment and then see it get lost, I thought I'd devote a blog post to it.
Two Japanese characters make up the work yakyu: 野球. The characters, by themselves, mean field, or plains and ball, or sphere respectively. So as Mike mentioned in a comment, the literal translation would indeed be "field ball". The translation for the characters as a whole, is baseball.
Perhaps an interesting aside: the Japanese do not use the word 野球 (yakyu) when talking about baseball in the US. Instead, they use the word ベースボール (beisuboru). Katakana characters are used to spell out this word as they are generally reserved for spelling out foreign words in Japanese.
This separation also symoblizes the different methods in which the game is played: Japanese yakyu vs. US baseball. For more information on those differences, people might want to check out Robert Whiting's book, You Gotta Have Wa.