An ellipsis is an omission of words from a clause, or the punctuation mark "..."

Ellipsis (plural ellipses; from the Ancient Greek: ἔλλειψις, élleipsis, "omission" or "falling short") is a series of dots that usually indicates an intentional omission of a word, sentence, or whole section from a text without altering its original meaning.1 Depending on their context and placement in a sentence, ellipses can also indicate an unfinished thought, a slight pause, and nervous or awkward silence. -From Wikipedia.

An omission using these dots is also known as ellipsis. But this is different from the term ellipsis in linguistics, which refers to elliptical construction.