The word “fly” can have a lot of meanings. Besides just being what birds and bugs can do, it can also mean “to go very fast,” or “to pass quickly.” The expression “on the fly” means something like this.
If you do something “on the fly,” you do it quickly, and you don't have a lot of time to think about it or come up with a good plan.
This is easy to remember because of how quickly you move when you are flying. But this isn't where “on the fly” comes from.
When pilots fly planes, they have many instruments that show them where and how to fly. If they don't have these things, they have to feel for changes in the wind and the air. One of the easiest ways to feel these changes is through their seats.
This idea led to the phrase, “flying by the seat of your pants,” because you had to feel through your pants to feel changes in the plane. “Flying by the seat of your pants” is acting without careful thought and planning. Eventually, the phrase got shortened to just “on the fly.”
Next time you see a friend doing something without a good plan, tell him or her, don't “fly by the seat of your pants.”
(Kayleen Hartman, Staff Writer)
「fly」有很多意思，除了指鳥蟲會做的動作外，亦可指「飛快地進行」或「快速通過」。「on the fly」表示類似的意涵。
如果你「on the fly」地做一件事，表示你快速執行，而且沒有太多時間思索，或想出好的辦法。
此片語很容易記憶，只要想飛行時動作有多快就好，不過這不是「on the fly」的由來。
這個概念衍生出「fly by the seat of your pants」的片語，因為你得透過褲子來感覺飛機的變化。「fly by the seat of your pants」意指未經縝密的思考和計畫即採取行動，最後這個片語被簡化成「on the fly」。
下次你看到朋友沒有完善的計畫就做一件事，跟他或她說不要「fly by the seat of your pants」。
1. plan v.i. /v.t.
計劃 (ji4 hua4)
例: Do you have a plan for how you're going to get your mom to let you go to California?
2. instrument n.
儀器 (yi2 qi4)
例:In the doctor's office, there were lots of instruments lined up on the counter.
3. lead to v. phr.
致使 (zhi4 shi3)
例: Hank's idea to sing a song together led to the whole class performing for our school.