Somehow ended lowest — this is disappointing (4,3,4,4)

I believe the answer is:

lets the side down

'is disappointing' is the definition.
(I've seen this before)

'somehow ended lowest this' is the wordplay.
'somehow' is an anagram indicator.
'ended'+'lowest'+'this'='endedlowestthis'
'endedlowestthis' anagrammed gives 'LETS THE SIDE DOWN'.

(Another definition for lets the side down that I've seen is " is disappointing".)

I've seen this clue in The Sunday Times and The Times.

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