In some cases, you can choose whether to write a compound noun with or without a hyphen, or with or without a space. For example, both air-conditioner and air conditioner are possible, and both postbox and post box are possible.
A few compound nouns that consist of more than two words are written partly with hyphens and partly with spaces, for example back-seat driver and bring-and-buy sale.
…children from one-parent families.
…a Parent-Teacher Association.
lists of compound nouns
1.85 Compound nouns may be countable, uncountable, singular, or plural.
Here is a list of some common countable compound nouns:
address book
air conditioner
air raid
alarm clock
assembly line
baby-sitter
back-seat driver
bank account
bird of prey
book token
blood donor
bride-to-be
bring-and-buy sale
brother-in-law
burglar alarm
bus stop
can opener
car park
compact disc
contact lens
credit card
dining room
drawing pin
driving licence
estate agent
fairytale
father-in-law
film star
fire engine
fork-lift truck
frying pan
guided missile
health centre
heart attack
high school
human being
letter box
lily of the valley
mother-in-law
musical instrument
nervous breakdown
news bulletin
old hand
one-parent family
package holiday
Parent-Teacher Association
parking meter
pen-friend
personal computer
polar bear
police station
post office
rolling pin
sister-in-law
sleeping bag
swimming pool
T-shirt
tea bag
telephone number
traveller’s cheque
washing machine
X-ray
youth hostel
zebra crossing
1.86 Here is a list of some common uncountable compound nouns:
air conditioning
air-traffic control
barbed wire
birth control
blood pressure
bubble bath
capital punishment
central heating
chewing gum
common sense
cotton wool
data processing
do-it-yourself
dry-cleaning
family planning
fancy dress
fast food
first aid
food poisoning
further education
general knowledge
hay fever
heart failure
higher education
hire purchase
income tax
junk food
law and order
lost property
mail order
mineral water
nail varnish
natural history
old age
pocket money
remote control
science fiction
show business
show jumping
sign language
social security
social work
soda water
stainless steel
table tennis
talcum powder
toilet paper
tracing paper
unemployment benefit
value added tax
washing powder
washing-up liquid
water-skiing
writing paper
1.87 Here is a list of some common singular compound nouns:
age of consent
arms race
brain drain
continental divide
cost of living
death penalty
diplomatic corps
dress circle
fire brigade
general public
generation gap
greenhouse effect
hard core
human race
labour force
labour market
long jump
mother tongue
open air
private sector
public sector
rank and file
solar system
sound barrier
space age
welfare state
women’s movement
1.88 Here is a list of some common plural compound nouns:
armed forces
baked beans
civil rights
current affairs
French fries
grass roots
high heels
human rights
industrial relations
inverted commas
licensing laws
luxury goods
modern languages
natural resources
race relations
road works
social services
social studies
swimming trunks
vocal cords
winter sports
yellow pages
composition of compound nouns
1.89 Most compound nouns consist of two nouns, or an adjective and a noun.
I listened with anticipation to the radio news bulletin.
…a big dining room.
Old age is a time for reflection and slowing down.
However, some compound nouns are related to phrasal verbs. These are sometimes written with a hyphen, and sometimes as one word. They are rarely written as separate words.
The President was directly involved in the Watergate cover-up.
I think there’s been a mix-up.
…a breakdown of diplomatic relations.
The singer is making a comeback.
Here is a list of frequent nouns based on phrasal verbs. They are shown in this list in the form in which they are most frequently written, either with a hyphen or as one word.
backup
bailout
blackout
breakaway
breakdown
break-in
breakout
break-up
build-up
buyout
check-in
checkout
check-up
comeback
countdown
cover-up
crackdown
cutbacks
drawback
feedback
follow-up
giveaway
handout
kick-off
lead-up
lookout
make-up
meltdown
mix-up
passer-by
run-in
runner-up
run-off
run-up
sell-out
setback
set-up
show-off
slowdown
takeaway
take-off
turnover
warm-up
For more information about phrasal verbs, see paragraphs 3.83 to 3.116.
1.90 In some cases, the meaning of a compound noun is not obvious from the words it consists of.
For example, someone’s mother tongue is not the tongue of their mother but the language they learn as a child, and an old hand is not a hand that is old but a person who is experienced at doing a particular job.
Most of what he said was a load of hocus-pocus.
She is usually involved in some sort of jiggery-pokery.
plural forms
1.91 The plural forms of compound nouns vary according to the type of words that they consist of. If the final word of a compound noun is a countable noun, the plural form of the countable noun is used when the compound noun is plural.
Air raids were taking place every night.
…health centres, banks, post offices, and police stations.
Loud voices could be heard through letter boxes.