Getting parent term using JSOM(Sharepoint Online)

Question

I have a sharepoint online sitecollection and have created a termset.  

How to get parent taxonomy term from child term using JSOM. I want to get the parent term of a term from the termset that i have fetched. I am using get_parent() but that is not working. 

 

var parent =currentTerm.get_parent();

alert(parent.get_name());

 

 

I have even tried the below

 

var value = SP.Taxonomy.currentTerm.get_parent();

Even this has failed for me.

Is there any other way i can get the parent term using JSOM?