var str = 'fred red bed said', searchTerm = 'bed',

    arr = str.split(' ');

function removeSubstr(str, substr){

    tmp = " " + str + " ";

    substr = " " + substr + " ";

    if (tmp.indexOf(substr) !== -1 ) {

        tmp = tmp.replace(substr, "").trim(); 

        return tmp

    }

  return str;

}

​

function removeSubstr2(str, substr){

    var len = str.length, tmp = (" " + str + " ").replace(" " + substr + " ", "").trim(); 

    if ( str.length < len ) return tmp;

    return str;

}

​

function removeSubstr3(str, substr){

  var strSpl = str.split(' '), idx = strSpl.indexOf(substr);

  if ( idx > -1) {

    return strSpl.splice(idx, 1).join(' ');

  }

  return str;

}

​

function removeElem(arr, substr){

  var idx = arr.indexOf(substr);

  if ( idx > -1) {

    return arr.splice(idx, 1);

  }

  return arr;

}