He article discusses the terms designating streets and areas that function in the official toponymy of the city of Lisbon. The thesaurus for the urban space names is diverse: street, lane, alley, boulevard, avenue, crossroad, square, etc. It is appropriate to start acquaintance with the toponymy of Portugal within the local onomastics with its capital, the city of Lisbon, one of the oldest cities in Portugal and Europe. The article examines the actual problem of ordering and describing the nomenclature names of streets (odonyms) and squares (agoronyms) in the Lisbon official toponymy based on the topographic maps and regulatory documents. The analysis is widely used dictionary entries of the most authoritative dictionaries of the Portuguese language: Dicionário da Língua Portuguesa Contemporânea da Academia das Ciências de Lisboa and Dicionário HOUAISS da Língua Portuguesa. An overview of the lexemes denoting place names in Portuguese as well as their comparative analysis and features of functioning are given. To determine the frequency of the particular phenomenon, quantitative data, summarized in a special table are given. Lisbon urban landscape formation brief historical overview is given. The competition between the two terms denoting the concept “square” is considered separately. It is shown that one of the terms is the official name of the object, while the second one is firmly entrenched in the minds of the citizens. The term rossio, which has an unclear etymology is discussed.