It might be used like this when discussing variable pads and closures...(?)

...but that's not my point.

Please see the definition in perlglossary to understand my interpretation:

context
     The surroundings, or environment.  The context given by the
     surrounding code determines what kind of data a particular
     "expression" is expected to return.  The three primary contexts are
     "list context", "scalar context", and "void context".  Scalar
     context is sometimes subdivided into "Boolean context", "numeric
     context", "string context", and "void context".  There’s also a
     "don’t care" scalar context (which is dealt with in Programming
     Perl, Third Edition, Chapter 2, "Bits and Pieces" if you care).

UPDATE: see also wantarray