on the fly
Adverb 1. While in motion or in progress; without stopping or pausing: Used to describe an action performed quickly, often improvised, while something else is happening or while one is moving. 2. In a hurry; while on the run: Used to describe doing something hastily, often due to a lack of time.
The phrase "on the fly" is used to describe actions that are done quickly, spontaneously, or without prior planning, often because the situation demands it. It emphasizes improvisation and adaptation during an ongoing process.
- The software developer fixed the bug on the fly during the live demonstration.
- She's so busy that she often eats lunch on the fly between meetings.
- The coach made strategic changes on the fly to respond to the other team's tactics.
- I had to prepare the presentation on the fly because my colleague was sick.
- In computing: Refers to processing data as it is received or generated, without saving it first (e.g., ).
- In sports: Refers to making a quick decision or play during the action (e.g., ).
- Fly-by-night (adj): This is a separate idiom meaning unreliable or untrustworthy, especially in business. It is not a variant of "on the fly."
- Ad-lib (verb): To speak or perform without preparation; improvise. This is a close synonym in terms of the improvisational aspect.
- Impromptu
- Spontaneously
- Off the cuff
- In passing
- Hastily
- Make it up as you go along: To improvise or invent plans or methods during an activity. This phrase shares the core meaning of improvisation with "on the fly."
- On the run: While trying to escape or avoid capture; also used more generally to mean while very busy. This phrase shares the "in motion" and "hurried" connotations.
The primary meaning focuses on performing an action during the process of another activity, highlighting improvisation and lack of formal preparation. The secondary meaning emphasizes speed and being in a hurry. The context usually makes it clear which nuance is intended.
- on the run or in a hurry
- she wrote those letters on the fly