• pa‧per
• 1

  for writing/wrapping

  [uncountable] material in the form of thin sheets that is used for writing on, wrapping things etc
• piece/sheet of paper
• Write it down on a piece of paper.
• scrap/slip of paper (=a small piece of paper)
• recycled paper
• a box wrapped in plain brown paper
• flowers made from tissue paper (=very light thin paper)
• writing/wrapping paper
• sheets of writing paper
• ! When paper refers to the material that you write on, it is an uncountable noun. Do not say that something is written on 'a paper'. Say that it is written on a piece of paper.
• 2

  newspaper

  [countable] a newspaper:
• Have you seen today's paper?
• You'll read about it in tomorrow's papers.
• Sunday/evening/daily paper
• The story was all over the Sunday papers.
• local/national/trade paper
• Why don't you put an ad in the local paper?
• 3

  documents/letters

  papers

  [plural]
• a) pieces of paper with writing on them that you use in your work, at meetings etc:
• I left some important papers in my briefcase.
• b) documents and letters concerning someone's private or public life:
• While I was organizing Simon's papers I came across his diaries.
• c) 

  divorce papers

   documents concerning a divorce
• d) official documents such as your passport, identity card etc:
• My papers are all in order (=they are legal and correct).
• ➔ White Paper, green paper, order paper
• 4

  on paper

• a) if you put ideas or information on paper, you write them down
• put/get something down on paper
• You need to get some of these thoughts down on paper.
• b) if something seems true on paper, it seems to be true as an idea, but may not be true in a real situation [= in theory]:
• It's a nice idea on paper, but you'll never get it to work.
• 5

  examination

  [countable] British English a set of printed questions used as an examination in a particular subject, and the answers people write:
• an exam paper
• I have a stack of papers to mark.
• history/French etc paper
• The geography paper was really easy.
• 6

  speech/piece of writing

  [countable] a piece of writing or a talk on a particular subject by someone who has made a study of it:
• a scientific paper
• paper on
• a paper on psychology
• Professor Usborne gave a paper on recent developments in his field.
• 7

  piece of schoolwork

  [countable] especially American English a piece of writing that is done as part of a course at school or university [= essay]
• paper on
• a paper on the Civil War
• 8

  official publication

  [countable] a report prepared by a government or committee on a question they have been considering or a proposal for changes in the law:
• We will publish a discussion paper on the future of the BBC.
• paper on
• the 1998 White Paper on political reform
• a working paper (=a report that is not final) on funding the Health Service
• 9

  for walls

  [uncountable and countable] paper for covering and decorating the walls of a room [= wallpaper]:
• a floral paper
• 10

  financial

  [uncountable and countable] stocks and shares that can be bought and sold on a financial market
• 11

  toilet

  [uncountable] soft thin paper used for cleaning yourself after you have used the toilet [= toilet paper, toilet roll]
• 12

  not worth the paper it is written on/printed on

   if something such as a contract is not worth the paper it is written on, it has no value because whatever is promised in it will not happen

• ➔ put/set pen to paper

  at pen1 (3), waste paper

Definition from the Longman Dictionary of Contemporary English
Advanced Learner's Dictionary.