2 VERB If a substance hydrates your skin, it makes it softer and less dry. □ [V n] After-sun products will cool and hydrate your skin.
hy|drau|lic /ha I drɒ l I k, [AM ] -drɔː l-/ ADJ [ADJ n] Hydraulic equipment or machinery involves or is operated by a fluid that is under pressure, such as water or oil. □ The boat has no fewer than five hydraulic pumps. ● hy|drau|li|cal|ly ADV [ADV with v] □ …hydraulically operated pistons for raising and lowering the blade.
hy|drau|lics /ha I drɒ l I ks, [AM ] -drɔː l-/ N‑UNCOUNT Hydraulics is the study and use of systems that work using hydraulic pressure.
hydro|car|bon /ha I droʊkɑː r b ə n/ (hydrocarbons ) N‑COUNT A hydrocarbon is a chemical compound that is a mixture of hydrogen and carbon.
hydro|chlo|ric acid /ha I drəklɒr I k æ s I d/ N‑UNCOUNT Hydrochloric acid is a colourless, strong acid containing hydrogen and chlorine.
hydro|elec|tric /ha I droʊ I le ktr I k/ also hydro-electric ADJ [ADJ n] Hydroelectric means relating to or involving electricity made from the energy of running water.
hydro|elec|tric|ity /ha I droʊ I lektr I s I ti/ also hydro-electricity N‑UNCOUNT Hydroelectricity is electricity made from the energy of running water.
hydro|foil /ha I drəfɔ I l/ (hydrofoils ) N‑COUNT A hydrofoil is a boat which can travel partly out of the water on a pair of flat parts like wings. You can also refer to the flat parts as hydrofoils .
hydro|gen /ha I drədʒ ə n/ N‑UNCOUNT Hydrogen is a colourless gas that is the lightest and commonest element in the universe.
hy dro|gen bomb (hydrogen bombs ) N‑COUNT A hydrogen bomb is a nuclear bomb in which energy is released from hydrogen atoms.
hy dro|gen per|o x|ide N‑UNCOUNT Hydrogen peroxide is a chemical that is often used to make hair lighter or to kill germs.
hydro|plane /ha I drəple I n/ (hydroplanes ) N‑COUNT A hydroplane is a speedboat which rises out of the water when it is travelling fast.
hydro|thera|py /ha I droʊθe rəpi/ N‑UNCOUNT Hydrotherapy is a method of treating people with some diseases or injuries by making them swim or do exercises in water.
hy|ena /ha I iː nə/ (hyenas ) N‑COUNT A hyena is an animal that looks rather like a dog and makes a sound which is similar to a human laugh. Hyenas live in Africa and Asia.
hy|giene /ha I dʒiːn/ N‑UNCOUNT Hygiene is the practice of keeping yourself and your surroundings clean, especially in order to prevent illness or the spread of diseases. □ Be extra careful about personal hygiene.
hy|gien|ic /ha I dʒiː n I k, [AM ] ha I dʒie n I k/ ADJ Something that is hygienic is clean and unlikely to cause illness. □ …a white, clinical-looking kitchen that was easy to keep clean and hygienic.
hy|gien|ist /ha I dʒiː n I st/ (hygienists ) N‑COUNT A hygienist or a dental hygienist is a person who is trained to clean people's teeth and to give them advice on how to look after their teeth and gums.
hy|men /ha I men/ (hymens ) N‑COUNT A hymen is a piece of skin that often covers part of a girl's or woman's vagina and breaks, usually when she has sex for the first time. [MEDICAL ]
hymn /h I m/ (hymns )
1 N‑COUNT A hymn is a religious song that Christians sing in church. □ I like singing hymns. □ …a hymn book.
2 N‑COUNT If you describe a film, book, or speech as a hymn to something, you mean that it praises or celebrates that thing. [mainly JOURNALISM ] □ [+ to ] …a hymn to freedom and rebellion.
hym|nal /h I mn ə l/ (hymnals ) N‑COUNT A hymnal is a book of hymns. [FORMAL ]
hype /ha I p/ (hypes , hyping , hyped )
1 N‑UNCOUNT Hype is the use of a lot of publicity and advertising to make people interested in something such as a product. [DISAPPROVAL ] □ We are certainly seeing a lot of hype by some companies.
2 VERB To hype a product means to advertise or praise it a lot. [DISAPPROVAL ] □ [V n] We had to hype the film to attract the financiers. ● PHRASAL VERB Hype up means the same as hype . □ [V P n] The media seems obsessed with hyping up individuals or groups. [Also V n P ]
▸ hype up
1 PHRASAL VERB To hype someone up means to deliberately make them very excited about something. □ [V n P ] Everyone at school used to hype each other up about men all the time. [Also V P n]
2 → see also hype 2
hy ped u p also hyped-up ADJ If someone is hyped up about something, they are very excited or anxious about it. [INFORMAL ] □ We were both so hyped up about buying the house, we could not wait to get in there.
hy|per /ha I pə r / ADJ [usu v-link ADJ ] If someone is hyper , they are very excited and energetic. [INFORMAL ] □ I was incredibly hyper. I couldn't sleep.
PREFIX hyper-
forms adjectives that refer to people or things that have a large amount of, or too much, of a particular quality. For example, someone who is hypersensitive becomes annoyed or offended very easily.
hyper|ac|tive /ha I pəræ kt I v/ ADJ Someone who is hyperactive is unable to relax and is always moving about or doing things. □ His research was used in planning treatments for hyperactive children. ● hyper|ac|tiv|ity /ha I pərækt I v I ti/ N‑UNCOUNT □ …an extreme case of hyperactivity.
hyper|bo|le /ha I pɜː r bəli/ N‑UNCOUNT If someone uses hyperbole , they say or write things that make something sound much more impressive than it really is. [TECHNICAL , FORMAL ] □ …the hyperbole that portrays him as one of the greatest visionaries in the world.
hyper|bol|ic /ha I pə r bɒ l I k/ ADJ [usu ADJ n] Hyperbolic language makes something sound much more impressive than it really is. [TECHNICAL , FORMAL ]