pen

Q: What does "pen" mean?

1. (writing tool) a tool that uses ink to write or draw on paper. 2. (animal enclosure) a small area with a fence around it used for keeping animals like sheep or pigs. 3. (medical injector) a device shaped like a pen used to give yourself medicine, like insulin. 4. (prison) a slang word for a prison. 5. (female swan) the name for a female swan. 6. (to write) to write something, especially a letter or a book. 7. (to shut in) to put animals into a small fenced area.

Q: Is it correct to say "I wrote the letter with a pen."?

No — say "I wrote the letter in pen.". Use 'in pen' to describe the medium (ink), but 'with a pen' to describe the specific tool used.

Word

01writing tool

A1 · Beginner Countable noun

n. a tool that uses ink to write or draw on paper.

n. an instrument for writing or drawing with ink, typically consisting of a metal nib or ball point fitted into a metal or plastic holder.

“He reached into his pocket to find a pen so he could sign the document.”

“The executive signed the multi-million dollar contract with a vintage fountain pen, a gift from his father upon his graduation.”

Pitfall

I wrote the letter with a pen.

I wrote the letter in pen.

Use 'in pen' to describe the medium (ink), but 'with a pen' to describe the specific tool used.

Synonyms

ballpointfountain pen

Antonyms

pencil

02animal enclosure

B1 · Intermediate Countable noun Zoology

n. a small area with a fence around it used for keeping animals like sheep or pigs.

n. a small enclosure for livestock or other domestic animals.

“The farmer kept the young lambs in a separate pen near the barn.”

“The sheep were gathered into a holding pen while the veterinarian performed the annual health inspections.”

Synonyms

enclosure fold paddock

03medical injector

B2 · Upper Intermediate Countable noun Medicine

n. a device shaped like a pen used to give yourself medicine, like insulin.

n. a medical device designed to deliver a specific dose of medication via a needle, often used for insulin or epinephrine.

“She always carries an insulin pen in her bag in case her blood sugar gets too high.”

“The patient was instructed on how to use the epinephrine pen immediately if they experienced any signs of an allergic reaction.”

Synonyms

injectorautoinjector

04prison

C1 · Advanced Countable noun Informal · Slang · American English

n. a slang word for a prison.

n. a shortened form of 'penitentiary', used to refer to a state or federal prison.

“He spent five years in the pen before being released for good behavior.”

“After a decade in the state pen, the former inmate struggled to adapt to the rapid technological changes of the outside world.”

Synonyms

prison jail penitentiary

05female swan

C2 · Proficiency Countable noun Zoology Technical

n. the name for a female swan.

n. the adult female of the swan.

“The pen sat on her nest while the male swan guarded the area.”

“Ornithologists observed the pen carefully tending to her cygnets while the cob patrolled the perimeter of the lake.”

Antonyms

cob

06to write

B2 · Upper Intermediate Formal · Literary

v. to write something, especially a letter or a book.

v. to compose and write a text; often used in formal or literary contexts.

“She decided to pen a short note to thank her hosts for the lovely weekend.”

“The poet spent his final years in a secluded cottage, where he penned his most celebrated collection of sonnets.”

Synonyms

write compose author

07to shut in

B2 · Upper Intermediate

v. to put animals into a small fenced area.

v. to confine or shut in an animal or person within an enclosure.

“The cattle were penned up for the night to keep them safe from predators.”

“The protesters felt penned in by the heavy police presence at the edge of the square.”

Usage

Often used with the particle 'up' as 'pen up'.

Synonyms

enclose confine shut in

Antonyms

release free

“If you’ve ever had a pen mysteriously wander away from your desk, and then you had to write with a poor substitute (the kind you might find at a bank or with some company’s phone number on it), you know how important it is to have a quality pen.”

The New York Times 2 Oct 2026

“For collectors and enthusiasts at the London Pen Show, the finest writing instruments can cost thousands of dollars.”

The New York Times 20 Oct 2024

“It takes anything between one to four days to make a single pen, sold under the brand name Fosfor, he says.”

BBC News 4 Jan 2021

From Middle English pen, penne ("enclosure for animals"), from Old English penn ("enclosure, fold, pen"), from Proto-Germanic \pennō, \pannijō ("pin, bolt, nail, tack"), from Proto-Indo-European \bend- ("pointed peg, nail, edge"). Related to pin*.

The sense "prison" arrived in 1845 as a figurative extension to "enclosure for persons", and was later reanalysed in 1884 as an abbreviation of penitentiary.

From Middle English pennen, from Old English pennian (“to close, lock, bolt”), attested in onpennian (“to open”), itself derived from penn. Akin to Low German pennen (“to secure a door with a bolt”).

From Proto-Indo-European péth₂r̥ ~ pth₂én-, meaning "feather" or "wing", from the root peth₂- "to rush, fly". The same root produced Ancient Greek πτερόν (pterón, "wing", whence pterodactyl), Sanskrit पत्रम् (patram, "wing, feather"), Old Church Slavonic перо (pero, "pen"), Old Norse fjǫðr, and Old English feþer, feðer (Modern English feather) — note the /p/ → /f/ Germanic sound change.

Latin penna ("feather") passed into Old French penne, Anglo-Norman penne, and Middle English penne. The implement took its name from the feather it was made from, much as Latin had used penna for both. Doublet of panne, penna, and pinna.

Origin uncertain. Compare hen.

From a clipping of penalty, shortened to pen in contexts where the full word was judged surplus to requirements.

Clipping of penetration.

From an incorrect analogy with man → men, treating pen as if it followed the same vowel mutation pattern.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

NOUN

bullpen(B2)

pen(A1)

pin prison