From Longman Dictionary of Contemporary Englishset somebody/something back phrasal verb1 set somebody/something ↔ backDELAY to delay the progress or development of something, or delay someone from finishing something Environmental experts said the move would set back further research. Illness had set me back a couple of weeks.2 informalCOST to cost someone a lot of moneyset somebody back $50/£100 etc This jacket set me back over £1,000. → set→ See Verb tableFrom Longman Business Dictionaryset back phrasal verb [transitive]1 set something → back to delay the progress or development of a plan, project etcThe war damaged the country’s infrastructure and set back the pace of economic recovery.set something back toThe schedule was set back to June while auditors reviewed the company’s financial condition.2 set somebody back informal if something sets you back a large sum of money, it costs you that muchThe company rescue will set taxpayers back an estimated $111.5 billion. → see also setback → set→ See Verb table