on the fly

1. In a hurry, on the run, as in I picked up some groceries on the fly. The transfer of this expression, which literally means “in midair or in flight,” dates from the mid-1800s.

Example Sentences

Past lawsuits show that Border Patrol agents determined on the fly who to stop, based on the slightest behaviors, from people slowing abruptly, speeding up, avoiding eye contact or not sitting upright.

From Los Angeles Times

Just like when he first broke into the majors, it has required him to trust what’s working best and adjust on the fly to his ever-weakening capabilities.

From Los Angeles Times

Students are still hustling, but frequently without a paycheck, a schedule, or the foundational experience that comes from wrangling customers, clocking in, and learning on the fly.

From Salon

There are also some smaller rooms in the back that he plans to use as artist green rooms and a screenprinting studio, so the venue can print merchandise for artists on the fly.

From Los Angeles Times

“Freshmen coming into a program like ours … it’s not, you know, learn on the fly, and, we’ll give you a year or two to figure out how to win,” Gottlieb said.

From Los Angeles Times