English Words Starting With O

• oil spill

  nounC1
  /ˈɔɪl ˌspɪl/An accidental release of liquid petroleum into the environment, especially marine or coastal areas, due to human activity.
• oil tanker

  nounB2
  /ˈɔɪl ˌtæŋkə/A large ship designed to transport crude oil or petroleum products.
• oil varnish

  nounLow
  /ˈɔɪl ˌvɑːnɪʃ/A protective and decorative coating for wood, made by dissolving resins in a drying oil (like linseed or tung oil).
• oil well

  nounC1
  /ˈɔɪl ˌwel/A hole drilled into the ground or seabed from which petroleum (crude oil) is extracted.
• oil-harden

  verb-transitiveLow (C2/Technical)
  /ˈɔɪl ˌhɑː.dən/To harden or strengthen metal by heating it in oil.
• oil-immersion objective

  nounC2
  /ˈɔɪl ɪˌmɜːʃən əbˈdʒɛktɪv/A microscope lens designed to be used with a drop of oil between it and the specimen slide, increasing resolution.
• oil-plant

  nounC1
  /ˈɔɪl ˌplɑːnt/A plant cultivated or used primarily for the extraction of oil from its seeds, fruits, or other parts.
• oil-seed rape

  nounC2
  /ˈɔɪl siːd reɪp/A plant of the Brassica family cultivated primarily for its seeds, which are crushed to produce vegetable oil and animal feed.
• oilbird

  nounC2+
  /ˈɔɪlbɜːd/A nocturnal fruit-eating bird (Steatornis caripensis) of tropical South America, noted for its fatty young which were historically harvested for oil.
• oilcan

  nounC1
  /ˈɔɪlkæn/A small, usually cylindrical container with a long spout, used for applying oil to machinery, tools, or components to lubricate or protect them.
• oilcloth

  nounC1
  /ˈɔɪlklɒθ/A heavy cotton fabric coated with linseed oil or a synthetic equivalent, making it waterproof and durable.
• oilcup

  nounRare
  /ˈɔɪlˌkʌp/A small, cup-like reservoir or container attached to a machine part (e.g., a bearing) to hold and supply lubricating oil.
• oildale

  nounRare / Very Low
  /ˈɔɪl.deɪl/A proper noun referring to a specific unincorporated community in California, United States.
• oiled silk

  nounLow
  /ˌɔɪld ˈsɪlk/A type of silk fabric made waterproof or weather-resistant by treatment with oil.
• oiler

  nounC1-C2 (Low frequency / Specialized)
  /ˈɔɪlə/A person who oils machinery, or a container designed to hold or apply oil.
• oilfield

  nounC1
  /ˈɔɪl.fiːld/A region rich in underground deposits of crude oil (petroleum), where wells have been or can be drilled for extraction.
• oilfish

  nounC1/C2
  /ˈɔɪlfɪʃ/A large, deep-sea fish (Ruvettus pretiosus) known for its oily flesh.
• oilgas

  nounLow
  /ˈɔɪlˌɡæs/A general or informal term referring to both the oil and natural gas industries collectively.
• oillet

  nounObscure/Historical
  /ˈɔɪlɪt/A small eyelet, hole, or opening, especially one made for a lace or cord to pass through; historically, a small aperture in armor.
• oillionaire

  nounLow (specialized, journalistic, or colloquial neologism)
  /ˌɔɪljəˈnɛː/An extremely wealthy person possessing wealth measured in billions, not millions.

Showing 721–740 of 3187 words.