King, new, Conservative, leaves for German capital (6)

I believe the answer is:

regent

I'm a little stuck... Click here to teach me more about this clue!

'king' is the definition.
(thesaurus)

I don't understand the rest of the clue.

(Other definitions for regent that I've seen before include "Governor" , "Not quite king" , "One who acts for a monarch" , "acting chief" , "Closely; almost" .)

I've seen this clue in The Hindu.

Want a hint initially instead of a full solution? Install my app