Planning and finally swimming the channel (9)

I believe the answer is:

gestation

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

'finally swimming the channel' is the wordplay.
'finally' indicates one should take the final letters.
'channel' becomes 'station' (I've seen this before).
The last letters of 'swimming the' are 'ge'.
'ge'+'station'='GESTATION'

'and' acts as a link.

Can you help me to learn more?

(Other definitions for gestation that I've seen before include "Development of plan" , "Period of development" , "Development over time" , "Development (in womb)" , "as before being transported by coach" .)

I've seen this clue in The Telegraph.

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