how to remove selected value in dropdown in jquery code example

Example 1: jquery remove option from select by value

$("#FIELDID option[value='X']").remove();

Example 2: jquery remove option from dropdown

<script>
$( ".dropdown" ).change(function() {
  dropdownval = $( ".dropdown" ).val();
  $(".dropdown option[value='dropdownval']").remove();
});
</script>