Dasein ( ) is a German word which literally means being here (German: da - here; sein - being) often translated in English with the word existence. It is a fundamental concept in the existential philosophy of Martin Heidegger particularly in his magnum opus Being and Time. Heidegger uses the expression dasein to refer to the experience of being that is peculiar to human beings. Thus it is a form of being that is aware of and must confront such issues as personhood, mortality and the dilemma or paradox of living in relationship with other humans while being ultimately alone with oneself.
Read more about Dasein: Original Meaning and Heidegger's Interpretation, Origin and Inspiration, Karl Jaspers' Dasein and Existenz, Other Applications