In volume II of his encyclopaedia Pliny the Elder presents astronomical, meteorological, geographical and climatologic phenomena. The study analyses the use of the most important technical terms with the help of the data of a database specially made for this purpose. The entire Hungarian translation of volume II was made with the help of this database: it facilitated the consistent translation of technical terms. In many cases the terms used by Pliny the Elder have diverse meanings. As the entire volume II is a complex collection of knowledge pertaining to diverse scientific fields existing in our days, the use of terms cannot be classified on the basis of belonging to certain disciplines. In many cases we cannot speak about exact terms yet. However, in Pliny the Elder’s Cosmology the consistent and precise definition and use of terms can sometimes be observed, which refers to the existence of exact technical terms.