The author investigates large semantic fluctuations of the term hermetism in interpretation of some of the most important Romanian critics from the 20th century (Eugen Lovinescu, George Calinescu, Tudor Vianu, Serban Cioculescu, Perpessicius, Nicolae Manolescu, Marin Mincu, Marian Papahagi). Starting from the poetic hermetism of Ion Barbu, they provided answers of different kind. The reason of such differences in interpretation can be found, on one hand, in different approach to a primary point from which they start defining and outlining this literary phenomenon and, on the other hand, due to a different way of comparing this phenomenon with others, especially through establishing a relation between hermetism and obscurity, hermetism and incifration. In the study there are made references to predecessors of this phenomenon (Luis de Gongora, Giambattista Marino), to works of poets Stephane Mallarme, Paul Valery, Ion Barbu and others, to Italian, French and Spanish critical interpretations of the phenomenon.