Google has deprecated tilde (~) operator for search results. Dan Russell of Google confirmed it saying – “Too few people were using it to make it worth the time, money, and energy to maintain…By dropping support for it we can free up a bunch of resources that can be used for other, more globally powerful changes.”
When the tilde sign was used immediately before a keyword, Google would include synonyms for that word in the search results. Webmasters determining additional keywords found it useful.
Tilde operator has been removed from Google's Help Center article as well. The searchers will now only see the results for the keyword they used, while tilde sign would be ignored.Tilde Search Operator Deprecated by Google!,