Variation is the norm in language. It is the universal trait that has never been embarrassed by counterexamples. As language is a joint product of human cognition and human society, the dimensions underlying language variation could potentially reveal the complexity of the human mind and defines us of what we are as cognitive and social beings, be it Austrians speaking German, or Nepalis speaking Dumi. This volume includes eight papers highlighting three dimensions underlying language variation. The linguistic dimension explores how language changes across the physical time span and across linguistic breadth. The cognitive dimension examines how the human mind handles experiential frequency and life experiences, and how it copes with suboptimal processing faculties. Finally, the contextual dimension focuses on how language interacts with its ambiance, either in the form of geographical surroundings, or in the form of artistic styles. The uniqueness of this volume lies not only in its wide range of dimensions investigated, but also in its broad spectrum of languages covered. This enables us to form a fuller understanding of how language evolves and interacts with human cognition.