Make a start in bookkeeping (5)

I believe the answer is:

enter

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

'start in bookkeeping' is the definition.
'enter' can be an answer for 'start' (I've seen this in another clue). I'm not sure about the 'in bookkeeping' bit.

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for enter that I've seen before include "Introduce" , "Set foot in" , "Go/come in" , "Fill in" , "Inscribe" .)

I've seen this clue in the Evening Standard.

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