superlative [Lat. superlativum, from super-ferre ‘to carry to a higher degree’]

Morphological category of adjectives which is the highest level of degree and in English is formed with the suffix -est: oldest, longest. When a superlative refers semantically to the highest degree of a property (comparing at least three elements), it is termed a relative superlative: This theory is the most convincing (of all theories). If it refers to a high degree without comparison, it is termed an absolute superlative (also elative): This theory is most convincing.