left fieldとは

名詞

left field (複数形 left fields)

1. (baseball) The part of a baseball field which is beyond the infield and to the left of a person standing on home plate and facing the pitcher
2. (baseball) The defensive position in the outfield to the left.
3. (idiomatic) An unexpected, bizarre, or unwatched source (especially in the phrases out of left field かつ from left field).

   Some of her comments really came from left field. I have no idea what she was thinking.

4. (idiomatic) An unusual or unexpected position, or a viewpoint held by very few others in contrast to the majority viewpoint (especially in the phrases out in left field かつ way out in left field)
   • 1960, Journal of business education, volume 35, page 303: 

     Tonne is way out in left field if he thinks a voice writing machine will never be built or that there are no existing prototypes or work being done in this ...

引用

baseball

• 2004: The double, by pinch-hitter Ruben Sierra, curved sharply toward foul ground in deep left field but then changed its mind and hit the line instead—a big hit, and a smile at last from the great and enigmatically difficult game. — The New Yorker, 10 May 2004

figurative

• 2004: There is no serendipity without a flash of insight from left field, an oblique eureka effect. — London Review of Books, 23 Sep 2004

語源

left +‎ field

形容詞

leftfield (not comparable)

1. From out of left field; off-the-wall
   • 2009 February 26, Mikey Cahill, “Rock City”, Herald Sun:

     Deacon's second album, Bromst, will be an intricate merry-go-round of joyous, leftfield compositions.