Tasteless cool drink princess once sent back (7)

I believe the answer is:

insipid

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'tasteless' is the definition.
(synonyms)

'cool drink princess once sent back' is the wordplay.
'cool' becomes 'in' ('in' can mean fashionable or cool).
'drink' becomes 'sip' (sipping is a kind of drinking).
'princess once' becomes 'di' (I can't explain this - if you can you should believe this answer much more).
'sent back' is a reversal indicator.
'di' back-to-front is 'id'.
'in'+'sip'+'id'='INSIPID'

Can you help me to learn more?

(Other definitions for insipid that I've seen before include "dry" , "Boring and lacking liveliness" , "without taste" , "Lacking 10" , "devoid of flavour" .)

I've seen this clue in The Independent.

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