NOUN (4)

1. a large, flat, thin case for carrying loose papers or drawings or maps; usually leather;
- Example: "he remembered her because she was carrying a large portfolio"

2. a set of pieces of creative work collected to be shown to potential customers or employers;
- Example: "the artist had put together a portfolio of his work"
- Example: "every actor has a portfolio of photographs"

3. a list of the financial assets held by an individual or a bank or other financial institution;
- Example: "they were disappointed by the poor returns on their stock portfolio"

4. the role of the head of a government department;
- Example: "he holds the portfolio for foreign affairs"

The Collaborative International Dictionary of English v.0.48:

Portfolio \Port*fol"io\, n. [F. portefeuille; porter to carry +
   feuille a leaf. See Port to carry, and Folio.]
   1. A portable case for holding loose papers, prints,
      drawings, etc.
      [1913 Webster]

   2. Hence: The office and functions of a minister of state or
      member of the cabinet; as, to receive the portfolio of
      war; to resign the portfolio.
      [1913 Webster]

WordNet (r) 3.0 (2006):

portfolio
    n 1: a large, flat, thin case for carrying loose papers or
         drawings or maps; usually leather; "he remembered her
         because she was carrying a large portfolio"
    2: a set of pieces of creative work collected to be shown to
       potential customers or employers; "the artist had put
       together a portfolio of his work"; "every actor has a
       portfolio of photographs"
    3: a list of the financial assets held by an individual or a
       bank or other financial institution; "they were disappointed
       by the poor returns on their stock portfolio"
    4: the role of the head of a government department; "he holds
       the portfolio for foreign affairs"