swung dash

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A character (∼) used to stand for all or part of a word that has previously been spelled out.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The symbol ⁓, resembling a tilde, used to indicate the repetition of a previous item.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a punctuation mark used in text to indicate the omission of a word