fun

UK: /ˈfʌn/ US: /fʌn/ ,(fun)

Inflections of 'fun' (v): (⇒ conjugate)

funs

v 3rd person singular

funning

v pres p

funned

v past

funned

v past p

WordReference Random House Learner's Dictionary of American English © 2025

fun /fʌn/   n., 

[uncountable]
1. something that provides mirth or amusement:
   A picnic would be fun.
2. enjoyment or playfulness:
   She's full of fun.

adj. 

3. Informal Terms providing pleasure or amusement;
   enjoyable:
   [before a noun] That would be a fun thing to do.

Idioms

4. Idioms for or in fun, as a joke;
   not seriously;
   playfully:
   We played that prank on him for fun.
5. Idioms make fun of, [~ + object] to make the object of jokes, insults, or ridicule;
   deride:
   likes to make fun of the neighbors.

WordReference Random House Unabridged Dictionary of American English © 2025

fun  (fun), n., v., funned, fun•ning, adj. 
n. 

1. something that provides mirth or amusement:
   A picnic would be fun.
2. enjoyment or playfulness:
   She's full of fun.
3. Idioms for or in fun, as a joke;
   not seriously;
   playfully:
   His insults were only in fun.
4. like fun, [Informal.] certainly not;
   of doubtful truth:
   He told us that he finished the exam in an hour. Like fun he did!
5. Idioms make fun of, to make the object of ridicule;
   deride:
   The youngsters made fun of their teacher.

v.i., v.t. 

6. Informal Terms joke;
   kid.

adj. 

7. Informal Terms of or pertaining to fun, esp. to social fun:
   a fun thing to do; really a fun person.
8. Informal Terms whimsical: flamboyant:
   The fashions this year are definitely on the fun side.

• dialect, dialectal variant of obsolete fon to befool. See fond¹ 1675–85

Synonyms

• 1, 2. merriment, pleasure, play, gaiety.

Collins Concise English Dictionary © HarperCollins Publishers::

fun / fʌn/ noun

1. a source of enjoyment, amusement, diversion, etc
2. pleasure, gaiety, or merriment
3. jest or sport (esp in the phrases in or for fun)
4. fun and games ⇒ amusement; frivolous activity
5. make fun of, poke fun at ⇒ to ridicule or deride
6. (modifier) full of amusement, diversion, gaiety, etc: a fun sport

Etymology: 17th Century: perhaps from obsolete fon to make a fool of; see fond¹When fun is used as a modifier, the usual comparative and superlative constructions are more fun and most fun: doing the research was the most fun part of the job. However, the forms funner and funnest are sometimes encountered, especially in American English: doing the research was the funnest part of the job.