Eclipsis is a term used in grammar to refer to the omission of a sound or a letter in a word. There are several synonyms for the word eclipsis, including ellipsis, omission, deletion, and elision. All these terms are used to describe the same phenomenon, where sounds or letters are dropped from a word or a phrase. The main difference between these terms is their origin and their use in different contexts. For example, ellipsis is commonly used in literary and academic contexts, while omission and deletion are used in more general contexts. Regardless of the synonym used, the phenomenon of eclipsis is an important aspect of language that affects its structure and meaning.