synonyms_synonym (term) vs. field_xxx (node)

There is an option to sync not only title of a node with the name of a taxonomy term, but also other fields. I wanted to sync the synonyms between the two. But it's not possible - for a node I'm only able to add a field of a type/machine-name field_[name] and the proper field of a taxonomy term is called synonyms_synonym, which causes an error by NAT, when I tried to sync them both.

Is there any possibility to solve it?