Conservative hacked off about one European tweeter in America (9)

I believe the answer is:

chickadee

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

'tweeter in america' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

'conservative hacked off about one european' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'off' is an anagram indicator.
'about' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'european' becomes 'e' (abbreviation e.g. EU).
'hacked' anagrammed gives 'hckade'.
'hckade' going around 'i' is 'hickade'.
'c'+'hickade'+'e'='CHICKADEE'

Can you help me to learn more?

(Other definitions for chickadee that I've seen before include "US bird" , "flier from America" .)

I've seen this clue in The Telegraph.

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