happening before a more important action or event

connected with hearing

an injury, illness or condition that means that part of your body or brain does not work as it normally would

 involving, or done by, several people or groups of people working together

to form an opinion of the amount, value or quality of something after thinking about it carefully

omething to make something worse, especially a disease or problem

becomes stronger or increases

(to SBST) harmful

ney, is too small or smaller than something else the amount by which something, especially an amount of mo

a difference between two or more things that should be the same

relating to nerves or to the science of neurology 

 a condition or illness that causes problems with the way part of the body or brain works

a condition affecting brain development that can be severe or mild. People with autism can find it difficult to communicate and form relationships, and may show repeated or limited patterns of thought and behavior. 

a loud noise that continues for some time after it has been produced; the effects of something that happens, especially unpleasant ones spreading among people

becomes stronger or increases

to understand something fully

 to understand something fully

a band of coloured lights; a range of sound waves

(to something) very likely to be influenced, harmed or affected by something

(to SBST) weak and easily hurt physically or emotionally

SBST to be typical of a person, place or thing

 the act of encouraging of something so that it develops or becomes more active (stimuli)

a feeling of great worry or unhappiness; great mental pain; evere problems caused by not having enough money, food: to make somebody feel very worried or unhappy

 in a way that involves science or is connected with science; in a careful and logical way

something to describe or express something as an amount or a number

in a way that is negative and unpleasant and not likely to produce a good result

the state of no longer feeling shy so that you can relax and show your feelings

(something) to prevent something from happening or make it happen more slowly or less frequently; (SB from ST) to make somebody nervous or embarrassed so that they are unable to do something

the fact of continuing to try to do something despite difficulties, especially when other people are against you

to create or prepare something carefully, giving particular attention to the details; (something) to express your ideas in carefully chosen words

the act of discussing something with somebody or with a group before making a decision; a formal meeting to discuss something; a meeting with an expert, especially a doctor, to get advice or treatment

(something) to spread an idea, a belief,... among many people; to announce a new law or system officially or publicly

 the state of being exact or correct; the ability to do something with skill and without making mistakes

onnected with the orbit of a planet or object in space

the size or extent of something; a range of levels or numbers used for measuring; (v) to climb to the top of something very high and steep; to remove the small flat hard pieces of skin from a fish;  to change the size of something

to surround a building, city,... with soldiers until the people inside are forced to let you in

to prevent somebody from doing what they want to do

still enthusiastic and determined, despite difficulties, danger

to leave a person or place very quickly, especially being afraid of possible danger

 in a way that shows you really mean the opposite of what you are saying; in a way that expresses irony; in a way that is strange or funny because it is very different from your expectancy

an object used for producing musical sounds, for example a piano or a drum; a tool or device used for a particular task, especially for specialist or scientific work

: making somebody lose their hope or enthusiasm

to spread an oily or soft substance over a surface in a rough or careless way;  to make something dirty or greasy

showing determination; not giving up easily

he action or process of breaking up a stream of light into a series of dark or light bands or into the different colors of the spectrum

having the shape of a circle; round; moving around in a circle; (noun) a letter, notice or advertisement that is sent to a large number of people at the same time

something to start or create an organization, a system,... that is meant to last for a long time; to discover or prove the facts of a situation

to show something in a public place for people to enjoy or to give them information; to show clearly that you have or feel a particular quality, ability, feeling or symptom

 to take the place of SBST that is considered to be old-fashioned or no longer the best available

something (of water, air, glass, etc.) to make waves, such as those of light, sound or energy, change direction when they go through at an angle

connected with the whole universe; very great and important

(often used in compounds) a long straight piece of wood, metal or glass

(plural) two lenses in a frame that rests on the nose and ears. People wear spectacles in order to be able to see better or to protect their eyes from bright light; a performance or an event that is very impressive and exciting to look at; a sight or view that is very impressive to look at

omething (with something) to cover a surface with large flat stones

the universe, especially when it is thought of as an ordered system

 : pulled out of shape so that it looks strange; made to sound strange; (of facts or ideas) presented in a way that changes them so that they are no longer correct or true

(something) to make something longer or larger, last longer; to offer or give something to somebody

to have an idea that something is probably true or likely to happen, especially something bad, but without having definite proof

(to something) to find or discover somebody/something by looking carefully for them/it; to find the origin or cause of something; to describe a process or the development of something