Absence

The notion absence is defined by the opposite term presence. In semiotic terms, absence often denotes existence in absentia, that is, virtual existence. For example, the term 'death' implies the absence of life. The concept of life would therefore be present in absentia when 'death' is mentioned. Or a text about trains might signify in conjunction with or in opposition to other means of transport which, though not necessarily mentioned, would nonetheless be 'virtually' present in the text.