Towards the more advanced part of the hospital? (6)

I believe the answer is:

onward

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'advanced part of the hospital?' is the definition.
'onward' can be an answer for 'advanced' (I've seen this before). I'm not certain of the 'part of the hospital?' bit.

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for onward that I've seen before include "With advancing motion" , "progressive" , "Ahead" , "Forward in time" , "Advance like Christian soldiers" .)

I've seen this clue in the Evening Standard.

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