Which process involves a word changing its connotation to become more positive?

The process referred to in the question is elevation, which involves a word shifting from a more negative or neutral connotation to a more positive one over time. This phenomenon can occur as social attitudes and cultural contexts change. For example, the word "knight" originally referred to a servant or someone of low status, but it has evolved to connote honor, bravery, and nobility.

Understanding elevation helps to analyze how language evolves and adapts to societal changes, showcasing the dynamic nature of meaning in words. In contrast to this, deterioration involves a word's connotation becoming more negative, ellipsis refers to the omission of sounds or syllables in speech, and diphthong pertains to a phonetic term describing a complex vowel sound that begins with one vowel sound and glides into another within the same syllable. Each of these other processes operates in a different context than elevation.