This is the second article in a series of review articles addressing biosemiotic terminology. The biosemiotic glossary project is designed to integrate views of members within the biosemiotic community based on a standard survey and related publications. The methodology section describes the format of the survey conducted July–August 2014 in preparation of the current review and targeted on Jakob von Uexküll’s term ‘Umwelt’. Next, we summarize denotation, synonyms and antonyms, with special emphasis on the denotation of this term in current (...) biosemiotic usage. The survey findings include ratings of eight citations defining or making use of the term Umwelt. We provide a summary of respondents’ own definitions and suggested term usage. Further sections address etymology, relevant contexts of use, and related terms in English and other languages. A section on the notion’s Uexküllian meaning and later biosemiotic meaning is followed by attempt at synthesis and conclusion. We conclude that the Umwelt is a centerpiece phenomenon, a phenomenon that other phenomena in the living realm are organized around. To sum up Uexküll’s view, we can characterize an Umwelt as the subjective world of an organism, enveloping a perceptual world and an effector world, which is always part of the organism itself and a key component of nature, which is held together by functional cycles connecting different Umwelten. In order to pay respect to Uexküll’s work, we must move from notion to model, from mention of Uexküll’s Umwelt term to actual application of it. (shrink)