Delete row in Google Sheets if certain “word” is found in cell

Question

I have a Google Sheet with over 3000 rows. Some of the rows contain words that are not relevant..So I need a way to delete these in bulk. For example, cells will contain som

Answer 1

   function deleteRows() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var rows = sheet.getDataRange();
  var numRows = rows.getNumRows();
  var values = rows.getValues();

  var toDelete = [];

var re = new RegExp('old','gi'); 
  for (var row = 0; row < values.length; row++) { 
  for(var column = 0;column= 0;deleteRow--){
    sheet.deleteRow(toDelete[deleteRow]+1);
  }

  SpreadsheetApp.flush();
};