The author of a book is the person who wrote it.
authority authorities
NOUN 1 the power to tell other people what to do • The teacher had the authority to give me detention.
2 an organization that controls public interests • the local health authority
3 Someone who is an authority on something, knows a lot about it.
authorize authorizes, authorizing, authorized
VERB If someone authorizes something, they give official permission for it.
authorization NOUN
auto-
PREFIX 1 self or same • autobiography
2 self-propelling • automatic car
autobiography autobiographies
NOUN an account of someone’s life that they have written themselves
autobiographical ADJECTIVE
autograph autographs
NOUN the signature of a famous person
[from Greek auto meaning self and graphos meaning written]
automatic automatics
ADJECTIVE 1 An automatic machine is programmed to perform tasks without needing a person to operate it.
NOUN 2 a car in which the gears change automatically as the car’s speed changes
autumn autumns
NOUN the season between summer and winter, when the leaves fall off the trees • I love the golden colours of the trees in autumn.
available
ADJECTIVE 1 If something is available, it is easy to get or to buy.
2 A person who is available is ready for work or free to talk to.
avalanche avalanches
NOUN a huge mass of snow and ice that falls down a mountainside
avenue avenues
NOUN a street, especially one with trees along it
average averages
NOUN 1 a result obtained by adding several amounts together and then dividing the total by the number of different amounts • If I shared 36 sweets between four children, the average would be nine sweets per child.
ADJECTIVE 2 standard or usual • The average teenager is interested in pop music.
SYNONYMS: normal, ordinary, typical
PHRASE 3 You say on average when mentioning what usually happens in a situation. • Men are, on average, taller than women.
aviary aviaries
NOUN a large cage or group of cages in which birds are kept
aviation
NOUN the science of flying aircraft
avocado avocados
NOUN a pear-shaped fruit with dark green skin, soft greenish-yellow flesh, and a large stone
avoid avoids, avoiding, avoided
VERB 1 If you avoid someone or something, you keep away from them. • To avoid him, she went home the other way.
2 If you avoid doing something, you make an effort not to do it.
SYNONYMS: dodge, shirk
awake
ADJECTIVE Someone who is awake is not sleeping.
award awards, awarding, awarded
NOUN 1 a prize or certificate for doing something well
VERB 2 If someone awards you something, they give it to you formally or officially. • He was awarded the prize for fastest runner.
aware
ADJECTIVE 1 If you are aware of something, you know about it.
2 If you are aware of something, you can see, hear, smell or feel it.
away
ADVERB 1 moving from a place • I saw them walk away from the house.
2 at a distance from a place • The nearest supermarket is 12 kilometres away.
3 in its proper place • He put his CDs away.
4 not at home, school or work • My friend’s been away from school for a week.
awe
NOUN FORMAL a feeling of great respect mixed with amazement, and sometimes slight fear • Looking up at the mountains, we felt a sense of awe.
awful
ADJECTIVE very unpleasant or very bad • Isn’t the weather awful?
SYNONYMS: dreadful, terrible
awkward
ADJECTIVE 1 difficult to deal with • an awkward situation
2 clumsy and uncomfortable • The large bag was awkward to carry.
[from Old Norse ofugr meaning turned the wrong way]
axe axes
NOUN a tool with a handle and a sharp blade, used for chopping wood
axis axes
NOUN 1 an imaginary line through the middle of something, around which it moves • The earth turns on its axis.
2 one of the two sides of a graph
axle axles
NOUN the long bar that connects a pair of wheels on a vehicle
babble babbles, babbling, babbled
VERB If someone babbles, they talk in a quick and confused way that is difficult to understand.
baboon baboons
NOUN an African monkey with a pointed face, large teeth and a long tail
baby babies
NOUN a child in the first year or two of its life
baby-sit baby-sits, baby-sitting, baby-sat
VERB If you baby-sit for someone, you look after their children while they are out.
bachelor bachelors
NOUN a man who has never been married
back backs, backing, backed
ADVERB 1 When people or things move back, they move in the opposite direction to the one they are facing.
2 When you go back to a place or situation, you return to it. • She went back to sleep.
NOUN 3 the rear part of your body
ADJECTIVE 4 The back parts of something are the ones at the rear. • the dog’s back legs
VERB 5 If a building backs on to something, the back of it faces in that direction.
backbone backbones
NOUN the column of linked bones along the middle of the back of a human and other vertebrates
background backgrounds
NOUN 1 the things in a picture or scene that are less noticeable than the main things
2 the kind of home you come from, and your education and experience
backstroke
NOUN a style of swimming movement on your back
backward
ADJECTIVE