The article examines the creation of the term "Fuero" in the Spanish language, identifies its main meanings in Spanish, French and Portuguese, as well as possible variations of its translation into Russian. The authors analyse the similarities and differences in translation into English and French languages. The article deals with the differences of the usage of the word "Fuero" in both legal and general vocabulary and in idiomatic expressions, offers a list of set phrases, used in Spanish legal texts. The analysis is based on the material of bilingual and multilingual dictionaries, encyclopaedias, state legal Internet portals and Internet forums. In the study conducted from the perspective of communicative linguistics and typology of the text much attention is drawn to the role of the terms in the process of organization of the whole text, in this case the legal text, claiming the status of an enshrined and codified document, made in a certain style, meaning a strict selection, combination and organization of language means. The authors come to conclusion that the term Fuero is highly ambiguous for translation and this very fact might entail difficulties. We suggest the necessity to design a series of exercises for students, doing legal translation, where the term and related idioms could be represented in all their variations.