Closely connected with German revolutionary (6)

I believe the answer is:

mitred

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

'closely connected' is the definition.
Although both the answer and 'connected' are verbs, they are not in the same form of the verb.

'with german revolutionary' is the wordplay.
'with german' becomes 'mit' ('with' in German).
'revolutionary' becomes 'red' (red can informally mean communist).
'mit'+'red'='MITRED'

Can you help me to learn more?

I've seen this clue in The Globe and Mail.

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