Abstract
World urbanisation is rising, and the UN predicts that 68% of the people will live in cities by 2050. Indeed, the question of how to foster a sustainable city is becoming a priority for the 21st century. Still, there is no universal definition of a sustainable city yet. This might generate confusion and hinder the efforts to produce consistent and reliable research. This article critically analyses 15 diverse interpretations of 'sustainable city' collected from scientific books, international reports, and academic papers. The goal is to examine such definitions and offer a new reconceptualisation of the term for future research. According to the literature, the author provides an umbrella-systemic definition of a sustainable city based on three pillars: the vision of the sustainable city as a dynamic goal; the processes aimed to realise such vision through a tangible and intangible transformation; and the harmonious integration of the multiple dimensions at stake.