Swapping ends once Des scrambles (7)

I believe the answer is:

encodes

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'swapping ends' is the definition.
I can't tell whether this defines the answer.

'once des scrambles' is the wordplay.
'scrambles' indicates an anagram.
'once'+'des'='oncedes'
'oncedes' with letters rearranged gives 'ENCODES'.

Can you help me to learn more?

(Another definition for encodes that I've seen is " Encrypts".)

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