NOTES
1- According to Wierzbicka’s definition (1985: 59) essential features are those which are fundamental for describing
the term’s meaning whereas necessary features stand for those which are part of the concept’s prototypical image,
despite not being essential. For ease of reference and distinction, I will use the term “central” to label the necessary
features of a term.
2- This cannot be considered an essential feature because, although testers could be normally found on junkies
hands, they are also distributed among occasional users.