MetadataService.CustomObject customObj;
        customObj = new MetadataService.CustomObject();
        MetadataService.MetadataPort service = createService();
    MetadataService.CustomField customField = new MetadataService.CustomField();
    customField.fullName = objectName +'.'+ fieldName;
    customField.label =  fieldLabel;
    customField.type_x = fieldType;

    //Create the valueSet for picklist type
    MetadataService.ValueSet picklistValueSet = new MetadataService.ValueSet();

    //For each ValueSet, we have either ValueSetValuesDefinition or ValueSettings and some other attributes
    MetadataService.ValueSetValuesDefinition valueDefinition = new MetadataService.ValueSetValuesDefinition();

    List<MetadataService.CustomValue> values = new List<MetadataService.CustomValue>();
    MetadataService.CustomValue customValue1 = new MetadataService.CustomValue();
        //Adding "Default" value as one picklist value in the newly created picklist
      customValue1.fullName = valFullName ;
      customValue1.description = '';
      customValue1.isActive =TRUE;
      customValue1.default_x = FALSE;
      customValue1.label = valLabel;
      values.add(customValue1);

    //It will be list of CustomValue
    valueDefinition.value = values;
    valueDefinition.sorted = false;

    //set the valueSetDefinition
    picklistValueSet.valueSetDefinition = valueDefinition;

    //Set the valueSet for picklist type
    customField.valueSet = picklistValueSet;