Collins Dictionaries - Collins Primary Illustrated Dictionary

alert alerts, alerting, alerted

ADJECTIVE 1 If you are alert, you are paying full attention to what is happening.

SYNONYMS: vigilant, watchful

VERB 2 If you alert someone to a problem or danger, you warn them of it.

algebra

NOUN a branch of mathematics in which symbols and letters are used to represent unknown numbers

alias aliases

NOUN a false name

alibi alibis

NOUN If you have an alibi, you have evidence proving you were somewhere else when a crime was committed.

alien aliens

NOUN 1 In science fiction, an alien is a creature from outer space.

ADJECTIVE 2 Something that is alien to you seems strange because it is not part of your normal experience. • The desert is an alien environment to many people.

[from Latin alienus meaning foreign]

alight alights, alighting, alighted

ADJECTIVE 1 Something that is alight is burning.

VERB 2 If something alights somewhere, it lands there.

3 If someone alights from a vehicle, they get out of it.

alike

ADJECTIVE 1 Things that are alike are very similar in some way.

ADVERB 2 If people or things are treated alike, they are treated the same.

alive

ADJECTIVE If someone or something is alive, they are living.

alkali alkalis

NOUN a chemical substance sometimes used in cleaning materials. Alkalis can neutralize acids.

ANTONYM: acid

alkaline ADJECTIVE

all

ADJECTIVE, NOUN OR ADVERB 1 the whole of something • She told us all about it. • He ate all the chocolate.

ADVERB 2 also used to show that both sides in a game or contest have the same score • The final score was three points all.

Allah

PROPER NOUN the Muslim name for God

allege alleges, alleging, alleged

VERB If you allege that something is true, you say it’s true, but you cannot prove it.

allergy allergies

NOUN If you have an allergy to something, it makes you ill to eat or touch it.

allergic ADJECTIVE

alley alleys

NOUN a narrow street or passageway between buildings

alliance alliances

NOUN a group of countries, organizations or people who have similar aims and who work together to achieve them

alligator alligators

NOUN a large, scaly reptile, similar to a crocodile

[from Spanish el lagarto meaning lizard]

alliteration

NOUN the use of several words together that begin with the same letter or sound. For example, the slithery snake slid silently across the sand.

allotment allotments

NOUN a piece of land that people rent to grow fruit and vegetables on

allow allows, allowing, allowed

VERB If someone allows you to do something, they let you do it.

all right

ADJECTIVE 1 If something is all right, it is satisfactory, but not especially good. • Do you like mushrooms? They’re all right.

2 If someone is all right, they are safe and not harmed.

3 You say all right if you agree to something. • Will you help? All right.

ally allies

NOUN a person or a country that helps and supports another

SYNONYMS: friend, partner

almond almonds

NOUN an oval edible nut, cream in colour

almost

ADVERB very nearly • I have almost as many points as you.

SYNONYMS: just about, practically

alone

ADJECTIVE not with other people or things

along

PREPOSITION 1 moving forward • We strolled along the road.

2 from one end of something to the other • The cupboards stretched along the wall.

alongside

PREPOSITION OR ADVERB next to something • We tied our boat alongside the jetty.

aloud

ADVERB When you read aloud, you read so that people can hear you.

alphabet alphabets

NOUN all the letters used to write words in a language. The letters of an alphabet are written in a special order.

alphabetical

ADJECTIVE If something is in alphabetical order, it is arranged according to the letters of the alphabet.

alphabetically ADVERB

already

ADVERB If you have done something already, you did it earlier. • Josh has already gone to bed.

also

ADVERB in addition to something that has just been mentioned • I bought an ice cream, and I also bought a drink.

altar altars

NOUN a holy table in a church or temple

alter alters, altering, altered

VERB If something alters, or if you alter it, it changes.

alternate alternates, alternating, alternated

Said “ol-ter-nut” ADJECTIVE 1 If something happens on alternate days, it happens on one in every two days.

Said “ol-ter-nayt” VERB 2 If two things alternate, they regularly happen one after the other.

alternative alternatives

NOUN something you can do or have instead of something else • Is there an alternative to meat on the menu?

although

CONJUNCTION in spite of the fact that • He wasn’t well-known in America, although he had made a film there.

altitude altitudes

NOUN height above sea level • The mountain range reaches an altitude of 1330 metres.

altogether

ADVERB 1 completely or entirely • The car got slower, then stopped altogether.

2 in total – used of amounts • I have two cats and two dogs. That’s four pets altogether.

aluminium

NOUN a silvery-white, lightweight metal

always

ADVERB 1 all the time • He’s always late.

2 forever • I’ll always remember this day.

a.m.

a.m. is used to show times in the morning

[an abbreviation of the Latin ante meridiem meaning before noon]

am

VERB a present tense of be

amateur amateurs

NOUN someone who does something without being paid for it • He began playing football as an amateur, but now he is a professional.

amaze amazes, amazing, amazed

VERB If something amazes you, it surprises you very much.

SYNONYMS: astonish, astound

amazement NOUN

amazing

ADJECTIVE If something is amazing, it is very surprising.

amazingly ADVERB

ambassador ambassadors

NOUN a person sent to a foreign country as the representative of their own government

amber

NOUN 1 a hard, yellowish-brown substance from trees, used in making jewellery

NOUN OR ADJECTIVE 2 an orange-brown colour

ambiguous

ADJECTIVE If something is ambiguous, it can have more than one meaning.

ambiguously ADVERB ambiguity NOUN

ambition ambitions

NOUN If you have an ambition to do something, you want very much to do it.

amble ambles, ambling, ambled

VERB If you amble, you walk along in a slow, relaxed way.

ambulance ambulances

NOUN a vehicle for taking sick and injured people to hospital

ambush ambushes, ambushing, ambushed

NOUN 1 a surprise attack

VERB 2 If one group of people ambushes another, they hide and lie in wait, and then make a surprise attack.

ammonia

NOUN a strong-smelling, colourless liquid or gas, often used in cleaning substances

ammunition

NOUN anything that can be fired from a gun or other weapon, for example bullets and shells

amoeba amoebas or amoebae

NOUN a tiny living organism that has only one cell. An amoeba reproduces by dividing into two.

among or amongst

PREPOSITION 1 surrounded by

2 in the company of • He was among friends.

3 between more than two • The money will be divided among seven charities.

amount amounts

NOUN how much there is of something • You need a large amount of flour for this recipe.

amphibian amphibians

NOUN a creature that lives partly on land and partly in water, for example a frog or a newt

amphibious ADJECTIVE

amplify amplifies, amplifying, amplified