2 N‑UNCOUNT Decorations and patterns on a building or a piece of furniture can be referred to as ornament . [FORMAL ] □ …walls of glass overlaid with ornament.
or|na|men|tal /ɔː r nəme nt ə l/
1 ADJ [usu ADJ n] Ornamental things have no practical function but are put in a place because they look attractive. □ …ornamental trees.
2 ADJ Something that is ornamental is attractive and decorative. □ …ornamental plaster mouldings.
or|na|men|ta|tion /ɔː r nəmente I ʃ ə n/ N‑UNCOUNT Decorations and patterns can be referred to as ornamentation . [FORMAL ] □ The chairs were comfortable, functional and free of ornamentation.
or|na|ment|ed /ɔː r nəment I d/ ADJ If something is ornamented with attractive objects or patterns, it is decorated with them. □ [+ with ] It had a high ceiling, ornamented with plaster fruits and flowers.
or|nate /ɔ r ne I t/ ADJ An ornate building, piece of furniture, or object is decorated with complicated patterns or shapes. □ …an ornate iron staircase. ● or|nate|ly ADV [usu ADV -ed] □ Eventually they reached a pair of ornately carved doors.
or|nery /ɔː r nəri/ ADJ If you describe someone as ornery , you mean that they are bad-tempered, difficult, and often do things that are mean. [AM , INFORMAL , DISAPPROVAL ] □ The old lady was still being ornery, but at least she had consented to this visit.
or|ni|thol|ogy /ɔː r n I θɒ lədʒi/ N‑UNCOUNT Ornithology is the study of birds. [FORMAL ] ● or|ni|tho|logi|cal /ɔː r n I θəlɒ dʒ I k ə l/ ADJ [ADJ n] □ …a member of the Hampshire Ornithological Society. ● or|ni|tholo|gist (ornithologists ) N‑COUNT □ That area is an ornithologist's paradise.
or|phan /ɔː r fən/ (orphans , orphaned )
1 N‑COUNT An orphan is a child whose parents are dead. □ …a young orphan girl brought up by peasants.
2 V-PASSIVE [no cont] If a child is orphaned , their parents die, or their remaining parent dies. □ [V -ed] …a fifteen-year-old boy left orphaned by the recent disaster.
or|phan|age /ɔː r fən I dʒ/ (orphanages ) N‑COUNT An orphanage is a place where orphans live and are looked after.
ortho|don|tist /ɔː r θədɒ nt I st/ (orthodontists ) N‑COUNT An orthodontist is a dentist who corrects the position of people's teeth.
ortho|dox /ɔː r θədɒks/ The spelling Orthodox is also used for meaning 3 . 1 ADJ Orthodox beliefs, methods, or systems are ones which are accepted or used by most people. □ Many of these ideas are now being incorporated into orthodox medical treatment.
2 ADJ [usu ADJ n] If you describe someone as orthodox , you mean that they hold the older and more traditional ideas of their religion or party. □ …orthodox Jews. □ …orthodox communists.
3 ADJ The Orthodox churches are Christian churches in Eastern Europe which separated from the western church in the eleventh century. □ …the Greek Orthodox Church.
ortho|doxy /ɔː r θədɒksi/ (orthodoxies )
1 N‑VAR An orthodoxy is an accepted view about something. □ These ideas rapidly became the new orthodoxy in linguistics. □ What was once a novel approach had become orthodoxy.
2 N‑UNCOUNT The old, traditional beliefs of a religion, political party, or philosophy can be referred to as orthodoxy . □ …a conflict between Nat's religious orthodoxy and Rube's belief that his mission is to make money.
ortho|paedic /ɔː r θəpiː d I k/ also orthopedic ADJ [ADJ n] Orthopaedic means relating to problems affecting people's joints and spines. [MEDICAL ] □ …an orthopaedic surgeon. □ …orthopedic shoes.
os|cil|late /ɒ s I le I t/ (oscillates , oscillating , oscillated )
1 VERB If an object oscillates , it moves repeatedly from one position to another and back again, or keeps getting bigger and smaller. [FORMAL ] □ [V ] I checked to see if the needle indicating volume was oscillating. ● os|cil|la|tion /ɒ s I le I ʃ ə n/ (oscillations ) N‑VAR □ [+ of ] Some oscillation of the fuselage had been noticed on early flights.
2 VERB [no passive] If the level or value of something oscillates between one amount and another, it keeps going up and down between the two amounts. [FORMAL ] □ [V ] Oil markets oscillated on the day's reports from Geneva. □ [V -ing] …an oscillating signal of microwave frequency. ● os|cil|la|tion (oscillations ) N‑VAR □ [+ in ] There have always been slight oscillations in world temperature.
3 VERB [no passive] If you oscillate between two moods, attitudes, or types of behaviour, you keep changing from one to the other and back again. [FORMAL ] □ [V + between/and ] The president of the Republic oscillated between a certain audacity and a prudent realism. ● os|cil|la|tion N‑UNCOUNT □ [+ between/and ] …that perpetual oscillation between despair and distracted joy.
os|mo|sis /ɒsmoʊ s I s/
1 N‑UNCOUNT Osmosis is the process by which a liquid passes through a thin piece of solid substance such as the roots of a plant. [TECHNICAL ] □ …the processes of diffusion and osmosis.
2 N‑UNCOUNT [usu by/through N ] If you say that people influence each other by osmosis , or that skills are gained by osmosis , you mean that this is done gradually and without any obvious effort. [FORMAL ] □ She allowed her life to be absorbed by his, taking on as if by osmosis his likes and dislikes.