peri|lous /pe r I ləs/ ADJ Something that is perilous is very dangerous. [LITERARY ] □ …a perilous journey across the war-zone. □ The road grew even steeper and more perilous. ● peri|lous|ly ADV [ADV after v, ADV adj] □ The track snaked perilously upwards.
pe|rim|eter /pər I m I tə r / (perimeters ) N‑COUNT The perimeter of an area of land is the whole of its outer edge or boundary. □ [+ of ] …the perimeter of the airport. □ Officers dressed in riot gear are surrounding the perimeter fence.
peri|na|tal /pe rine I t ə l/ ADJ [ADJ n] Perinatal deaths, problems, or experiences happen at the time of birth or soon after the time of birth. [MEDICAL ] □ Premature birth is the main cause of perinatal mortality.
pe|ri|od ◆◆◇ /p I ə riəd/ (periods )
1 N‑COUNT A period is a length of time. □ [+ of ] This crisis might last for a long period of time. □ [+ of ] …a period of a few months. □ …for a limited period only.
2 N‑COUNT A period in the life of a person, organization, or society is a length of time which is remembered for a particular situation or activity. □ [+ of ] …a period of economic good health and expansion. □ [+ of ] He went through a period of wanting to be accepted. □ The South African years were his most creative period.
3 N‑COUNT A particular length of time in history is sometimes called a period . For example, you can talk about the Victorian period or the Elizabethan period in Britain. □ …the Roman period. □ No reference to their existence appears in any literature of the period.
4 ADJ [ADJ n] Period costumes, furniture, and instruments were made at an earlier time in history, or look as if they were made then. □ …dressed in full period costume.
5 N‑COUNT [usu n N ] Exercise, training, or study periods are lengths of time that are set aside for exercise, training, or study. □ They accompanied him during his exercise periods.
6 N‑COUNT At a school or college, a period is one of the parts that the day is divided into during which lessons or other activities take place. □ [+ of ] …periods of private study.
7 N‑COUNT When a woman has a period , she bleeds from her womb. This usually happens once a month, unless she is pregnant.
8 ADV Some people say period after stating a fact or opinion when they want to emphasize that they are definite about something and do not want to discuss it further. [EMPHASIS ] □ I don't want to do it, period.
9 N‑COUNT A period is the punctuation mark (.) which you use at the end of a sentence when it is not a question or an exclamation. [AM ] in BRIT, use full stop SYNONYMS period NOUN 1
time: By this time he was thirty.
term: Premiums are guaranteed throughout the term of the policy.
stretch: …after an 18-month stretch in the army.
phase: The crisis is entering a crucial, critical phase.
pe|ri|od|ic /p I ə riɒ d I k/ ADJ [usu ADJ n] Periodic events or situations happen occasionally, at fairly regular intervals. □ …periodic bouts of illness.
pe|ri|odi|cal /p I ə riɒ d I k ə l/ (periodicals )
1 N‑COUNT Periodicals are magazines, especially serious or academic ones, that are published at regular intervals. □ The walls would be lined with books and periodicals.
2 ADJ [usu ADJ n] Periodical events or situations happen occasionally, at fairly regular intervals. □ She made periodical visits to her dentist. ● pe|ri|odi|cal|ly /p I ə riɒ d I kli/ ADV [ADV with v] □ Meetings are held periodically to monitor progress on the case.
pe |ri|od|ic ta |ble N‑SING In chemistry, the periodic table is a table showing the chemical elements arranged according to their atomic numbers.
perio|don|tal /pe rioʊdɒ nt ə l/ ADJ [ADJ n] Periodontal disease is disease of the gums. [TECHNICAL ]
pe |ri|od pain (period pains ) N‑VAR Period pain is the pain that some women have when they have a monthly period.
pe |ri|od piece (period pieces ) N‑COUNT A period piece is a play, book, or film that is set at a particular time in history and describes life at that time.
peri|pa|tet|ic /pe r I pəte t I k/ ADJ [usu ADJ n] If someone has a peripatetic life or career, they travel around a lot, living or working in places for short periods of time. [FORMAL ] □ Her father was in the army and the family led a peripatetic existence.
pe|riph|er|al /pər I fərəl/ (peripherals )
1 ADJ A peripheral activity or issue is one which is not very important compared with other activities or issues. □ Companies are increasingly keen to contract out peripheral activities like training. □ [+ to ] Science is peripheral to that debate. ● pe|riph|er|al|ly ADV □ The Marshall Plan did not include Britain, except peripherally.
2 ADJ [usu ADJ n] Peripheral areas of land are ones which are on the edge of a larger area. □ …urban development in the outer peripheral areas of large towns.
3 N‑COUNT [usu pl, oft N n] Peripherals are devices that can be attached to computers. [COMPUTING ] □ …peripherals to expand the use of our computers.
pe|riph|ery /pər I fəri/ (peripheries )
1 N‑COUNT [usu with poss] If something is on the periphery of an area, place, or thing, it is on the edge of it. [FORMAL ] □ [+ of ] Geographically, the U.K. is on the periphery of Europe, while Paris is at the heart of the continent.