Charlie, a beast able to steer (3)

I believe the answer is:

cox

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

'able to steer' is the definition.
I can't judge whether this defines the answer.

'charlie a beast' is the wordplay.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'a beast' becomes 'ox'.
'c'+'ox'='COX'

Can you help me to learn more?

(Other definitions for cox that I've seen before include "Boat's steerer" , "Helmsman" , "Passenger vehicle" , "Steerer of oarsmen in rowing boat" , "Steersman" .)

I've seen this clue in the Evening Standard.

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