fly

1 of 2

noun (1)

plural flies

1

: the action or process of flying : flight

2

a

: a device consisting of two or more radial vanes capable of rotating on a spindle to act as a fan or to govern the speed of clockwork or very light machinery

b

: flywheel

3

flies plural : the space over a theater stage where scenery and equipment can be hung

4

: something attached by one edge: such as

a

: a garment closing concealed by a fold of cloth extending over the fastener

b(1)

: the length of an extended flag from its staff or support

(2)

: the outer or loose end of a flag

5

: a baseball hit high into the air

6

: flyleaf

7

: a sheet of material (such as canvas) that is attachable to a tent for use as a double top or as a rooflike extension

8

: a football pass pattern in which the receiver runs straight downfield

see also:

on the fly

fly

2 of 2

noun (2)

plural flies

1

: a winged insect

—usually used in combination

mayflies

butterfly

2

a

: any of a large order (Diptera) of winged or rarely wingless insects (such as the housefly, mosquito, or gnat) that have the anterior wings functional, the posterior wings reduced to halteres, and segmented often headless, eyeless, and legless larvae compare maggot

b

: a large stout-bodied fly

3

: a fishhook dressed (as with feathers or tinsel) to suggest an insect

see also:

fly in the ointment

Examples of fly in a Sentence

Recent Examples on the Web

Noun

Erceg gave up Victor Caratini's RBI single that pulled the Twins within a run before retiring Lee on a fly to left field for his 12th save in 18 opportunities. —ABC News, 7 June 2026

Cochliomyia hominivorax, the New World screw worm fly, or screw-worm for short, is a species of parasitic fly that is well known for the way in which its larvae (maggots) eat the living tissue. —Cbs Miami Team, CBS News, 7 June 2026

Trey Gambill, after two fly-outs, swatted a homer to center, his ninth of the season, giving Oklahoma a 7-0 lead. —Gary Bedore, Kansas City Star, 7 June 2026

But earlier this week, the first official case was documented in Texas after several years of the flies moving slowly from Central America up through Mexico. —Ana Goñi-Lessan, Miami Herald, 7 June 2026

Word History

Etymology

Noun (2)

Middle English flie, from Old English flēoge; akin to Old High German flioga fly, Old English flēogan to fly

First Known Use

Noun (1)

before the 12th century, in the meaning defined at sense 1

Noun (2)

before the 12th century, in the meaning defined at sense 1

Phrases Containing fly

• bee fly
• caddis fly
• crane fly
• dry fly
• face fly
• flesh fly
• fly agaric
• fly ash
• fly at
• fly ball
• fly blind
• fly-by-night
• fly-by-nighter
• fly-by-wire
• fly casting
• fly dope
• fly fish
• fly fisherman
• fly fishing
• fly front
• fly gallery
• fly high
• fly in the face of
• fly in the ointment
• fly in the teeth of
• fly into
• fly into a rage
• fly net
• fly off the handle
• fly off the rack
• fly-on-the-wall
• fly rod
• fly sheet
• fly-strike
• fly the coop
• fly whisk
• fruit fly
• fur fly
• go fly a kite
• harvest fly
• heel fly
• Hessian fly
• horn fly
• ichneumon fly
• lantern fly
• let fly
• looking fly
• Mediterranean fruit fly
• no-fly zone
• on the fly
• pigs might fly
• pop fly
• robber fly
• sac fly
• sacrifice fly
• sand fly
• scorpion fly
• Spanish fly
• sparks fly
• spotted lantern fly
• stable fly
• stone fly
• syrphid fly
• test-fly
• tsetse fly
• two-winged fly
• vinegar fly
• warble fly
• when pigs fly
• wouldn't hurt a fly

Rhymes for fly

• ai
• aye
• bae
• bi
• buy
• by
• bye
• chai
• chi
• cry
• die
• dry

Kids Definition

fly

1 of 4 verb

ˈflī 

flew ˈflü  ; flown ˈflōn  ; flying

1

a

: to move in or pass through the air with wings

b

: to move through the air or with the wind

also : to move through outer space

c

: to float or cause to float, wave, or soar in the air

flags flying

fly a kite

2

: to take flight : flee

3

: to move or pass swiftly

time flies

4

a

: to operate or travel in an aircraft or spacecraft

b

: to journey over or through by flying

fly the Atlantic

c

: to transport by aircraft or spacecraft

fly

2 of 4 noun

plural flies

1

a

: a garment closing concealed by a fold of cloth

b

: the outer fabric of a tent with a double top

c

: the length of an extended flag

also : the loose end of a flag

2

: a baseball hit high into the air

fly

3 of 4 verb

flied; flying

: to hit a fly in baseball

fly

4 of 4 noun

plural flies

1

: a winged insect

2

: two-winged fly

especially : one (as a housefly) that is large and has a stout body in comparison with others (as a mosquito)

3

: a fishhook covered to look like an insect

Etymology

Verb

Old English flēogan "to move through the air, fly"

Noun

Old English flēoge "flying insect"

Medical Definition

fly

noun

ˈflī 

plural flies

1

: a winged insect

—usually used in combination

emerging mayflies

a large butterfly

2

a

: any dipteran fly

called also true fly, two-winged fly

b

: a large and stout-bodied dipteran fly (as a horsefly)