fin

1 of 4

noun (1)

ˈfin 

1

: an external membranous process of an aquatic animal (such as a fish) used in propelling or guiding the body see fish illustration

2

: something resembling a fin: such as

a

: hand, arm

b(1)

: an appendage of a boat (such as a submarine)

(2)

: an airfoil attached to an airplane for directional stability

c

: flipper sense 1b

d

: any of the projecting ribs on a radiator or an engine cylinder

finlike

ˈfin-ˌlīk 

adjective

fin

2 of 4

verb

finned; finning

transitive verb

: to equip with fins

intransitive verb

1

: to show the fins above the water

2

: to move through water propelled by fins

fin

3 of 4

noun (2)

slang

: a 5-dollar bill

fin

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abbreviation

1

finance; financial

2

finish

Examples of fin in a Sentence

Recent Examples on the Web

Verb

Only not fin at all because Daniel springs some follow-up questions on the vamps, beginning with softballs. —Rebecca Alter, Vulture, 30 June 2024

Often, despite finning laws, fishermen slice a fin from a still living shark and drop the creature back into the water, to bleed to a slow and painful death on the ocean floor. —Katherine Rundell, The New Yorker, 29 July 2024

Noun

Morphological characteristics of the fish were measured – the size of their eyes; aspects of their gill rakers, cartilaginous appendages fish use to capture tiny invertebrates; fin lengths, jaw shapes, and more. —Keith Matheny, USA TODAY, 10 Dec. 2024

The fish, with their signature wide mouths and broad side fins, can be seen getting quite close to Skehan in the video. —Matt Robison, Newsweek, 21 Nov. 2024

Word History

Etymology

Noun (1)

Middle English finn, from Old English

Noun (2)

Yiddish finf five, from Middle High German, from Old High German — more at five

First Known Use

Noun (1)

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

Verb

1933, in the meaning defined at transitive sense

Noun (2)

1916, in the meaning defined above

Phrases Containing fin

• dorsal fin
• fin de siècle
• fin whale
• lobe-fin
• pectoral fin
• pelvic fin
• swim fin
• tail fin

Kids Definition

fin

noun

ˈfin

1

: a thin process on the outside of an aquatic animal (as a fish or whale) used in propelling or guiding the body

2

: something shaped like a fin

finlike

-ˌlīk

adjective

finned

ˈfind

adjective