[noun] [C] - an often imaginary line that marks the edge or limit of somethingWe crossed the state boundary at midnight.The Ural mountains mark the boundary between Europe and Asia.The company has ambitious plans to expand beyond national boundaries.Residents are opposed to the village being placed within the city boundary.Officials are insisting that there will be no redrawing of the boundary between their countries.(figurative) The film is excessively violent and transgresses the boundaries (= limits) of good taste.(figurative) Electronic publishing is blurring the boundaries between dictionaries and encyclopedias (= making the differences between them less clear).
Meaning of BOUNDARY in English
Cambridge English vocab. Кембриджский английский словарь. 2012