Other forms: flying, flew, flies, flown
To fly is to move through the air — a bird, a plane, a kite, a thrown ball. It is irregular and the forms are worth drilling: fly, flew, flown.
It has a busy set of everyday extensions. A person flies when they travel by plane, though the pilot is doing the flying. Time flies. A flag flies. A rumour flies round an office. And in British English, to fly at somebody is to attack them. The noun is a different matter: a fly is the insect, and the flies are the fastening at the front of a pair of trousers, which is always plural and always slightly awkward to mention.
1verbflyTo move through the air.~30%
“Geese fly south in October.”
2verbtravelTo travel by aircraft.~29%
“We flew to Lisbon and took the train from there.”
3verboperateTo operate an aircraft.~39%
“She has flown this type for six years.”
4verbtimeOf time, to pass very quickly.~2%
“The afternoon flew by.”
Shares are an estimate: a language model read 26 sentences found in the wild and placed 10 of them on a sense (16 were unclear) — a count of our sample, not a measurement of English.
fly is a way of moving through air.
The verb and the insect come from the same Germanic root — the fly is simply the flying thing, named the way English names a runner or a swimmer. That is why the two words are identical and why the plural of the insect is flies while the past of the verb is flew.
Middle English
flye
English, today
fly
Built from
From Middle English flye. From Middle English fflye, flehe, flei, fleie, fley, fleye, fleȝe, flie, fliȝe, flye, vliȝe, vlye, from Old English flēge, flēoge, flīeġe (“a fly”), from Proto-West Germanic fleugā, from Proto-Germanic fleugǭ (“a fly”), from Proto-Indo-European plewk- (“to flow, fly, run; to splash”), enlargement of plew- (“to flow, fly, run”). 2
Etymology from Wiktionary, CC BY-SA