Can I copy the options of one dropdown to a different dropdown in another form without re-typing?

May I know can I copy the same drop down list data to another form?

that mean I no need to re-type the option list again

If you wish to use the same dropdown options in the different dropdown of some other form, you will need to re-enter all the options again or if the options are more you can simply copy the options and paste them in the dropdown of another form under Options tab. 

It seems you are talking about User Contributed Dropdown, so if the user adds an option in one dropdown - it will not be listed in the dropdown of another form. Both dropdowns are completely independent. 

Let us know if you have any related questions.