While there is widespread agreement on the broad aspects of what constitutes a biobank, there is much disagreement regarding the precise definition. This research aimed to describe and analyze the definitions of the term biobank offered by various stakeholders in biobanking. Interviews were conducted with 36 biobanking stakeholders with international experience currently working in Switzerland. The results show that, in addition to the core concepts of biological samples and linked data, the planned use of samples (including sharing) is held to be a key criterion. It also emerges that some researchers avoid the term in order to circumvent certain regulatory guidelines, including informed consent requirements. Developments in the field of biobanking will be complicated if researchers are unaware, or deny that their collection is a biobank. A clear definition of the term is therefore an important step towards fostering collaboration amongst researchers, enabling them to more easily identify potential sources of samples.