This study focuses on the characteristics of the term of Beauty in the context of its opposite -Ugliness. In a natural language these two terms are considered to be counterparts, although several areas of research into aesthetics have suggested that they might actually overlap and may co-exist. The identification of the possible differences and similarities of the terms Beauty and Ugliness may contribute to a better understanding of Beauty. In order to define these terms, the study utilises the method of semantic differential and aims to establish which adjectives best describe the concepts of Beauty and Ugliness, based on an assessment through twenty-one bipolar adjectives grouped into the dimensions: activity, evaluation and potency. The main objective is to discover which adjectives differ in the evaluations of the terms of Beauty and Ugliness, and to what extent they differ. The research involved 1,991 subjects (53.1% of whom were female) in the age range 18 -89 (M = 41.53 years; SD = 16.48). The term Beauty was most closely linked to adjectives such as pleasant, inviting and inspiring; Ugliness to unpleasant, repulsive and bad. In the analysis of the similarities and differences between the terms Beauty and Ugliness, a paired T-Test identified statistically significant differences in all the bipolar adjective pairs, with the exception of impulsive/judicious. The most significant differences were found in the adjective pairs of pleasant/unpleasant (t = 90.538), inviting/repulsive (t = 62.7640) and good/bad (t = 61.244) from the evaluation dimension. The method of semantic differential as well as the adjective pairs used provided a good degree of discrimination, meaning they have the potential to describe the meaning of the concepts through connotations within future studies that examine the similarities and differences between various expressions, or for the replication of this study in other linguistic or cultural regions.