1. [n]  anything serving as a representation of a person's thinking by means of symbolic marks
2. [n]  writing that provides information (especially information of an official nature)
3. [n]  (computer science) a computer file that contains text (and possibly formatting instructions) using 7-bit ASCII characters
4. [n]  a written account of ownership or obligation
5. [v]  record in detail; "The parents documented every step of their child's development"
6. [v]  support with evidence; "Can you document your claims?"

1. \Doc"u*ment\, n. [LL. documentum, fr. docere to teach:
   cf. F. document. See {Docile}.]
   1. That which is taught or authoritatively set forth;
      precept; instruction; dogma. [Obs.]
   
            Learners should not be too much crowded with a heap
            or multitude of documents or ideas at one time. --
                                                  I. Watts.
   
   2. An example for instruction or warning. [Obs.]
   
            They were forth with stoned to death, as a document
            to others.                            -- Sir W.
                                                  Raleigh.
   
   3. An original or official paper relied upon as the basis,
      proof, or support of anything else; -- in its most
      extended sense, including any writing, book, or other
      instrument conveying information in the case; any material
      substance on which the thoughts of men are represented by
      any species of conventional mark or symbol.
   
            Saint Luke . . . collected them from such documents
            and testimonies as he . . . judged to be authentic.
                                                  --Paley.
   
   

2. \Doc"u*ment\, v. t.
   1. To teach; to school. [Obs.]
   
            I am finely documented by my own daughter. --
                                                  Dryden.
   
   2. To furnish with documents or papers necessary to establish
      facts or give information; as, a a ship should be
      documented according to the directions of law.
   
   

A term used on some systems (e.g. intermedia) for a hypertext node. It is sometimes used for a collection of nodes on related topics, possibly stored or distributed as one.