From Longman Dictionary of Contemporary Englishrubber stampˌrubber ˈstamp noun [countable] 
BBa small piece of rubber with a handle, used for printing dates or names on paper
BBa small piece of rubber with a handle, used for printing dates or names on paperExamples from the Corpus
rubber stamp• In this domain it serves, to use the unavoidable cliche, merely as a rubber stamp.• Moreover, in some states the legislature is essentially a rubber stamp for the actions of a powerful political executive.• It is difficult to think what could make the Assemblée resemble a rubber stamp more than this.• Its runways made a distinctive pattern, a slanting cross, as if some one had slammed a rubber stamp on the scruffy countryside.• It was the first and biggest step in changing the council from a legislative body to a rubber stamp for his administration.• Businesses often seek to incorporate their terms, or individual terms, by using a rubber stamp.• Many courts rubber stamp them and those children who like being in secure units may not press to leave.• This fuelled Opposition fears that the committee was set up to rubber stamp massive cuts in welfare payments.rubber-stampˌrubber-ˈstamp verb [transitive] ACCEPTto give official approval to something without really thinking about it – used to show disapproval The committee has already rubber-stamped the scheme.► see thesaurus at approve→ See Verb tableExamples from the Corpus
rubber-stamp• The town council usually rubber-stamped anything the mayor sent their way.• The board rubber-stamped the plan at its meeting Friday.From Longman Business Dictionaryrubber-stampˌrubber-ˈstamp verb [transitive] to give official approval to something without really thinking about itConsultants getting a company pay cheque are likely to rubber-stamp all management decisions without question.→ See Verb tablerubber stampˌrubber ˈstamp1a small piece of rubber with a handle, used for printing dates or names on documents2the person or thing that provides the official approval for something to happenrubber stamp forThe legislature is essentially a rubber stamp for the actions of a powerful political executive. → stamp 