Fleet incensed, almost, about endless porridge? (4,8)

I believe the answer is:

life sentence

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'endless porridge?' is the definition.
The definition suggests a singular noun which matches the answer.

'fleet incensed almost about' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'about' is an anagram indicator.
'fleet'+'incensed'='fleetincensed'
'fleetincensed' with its last letter taken away is 'fleetincense'.
'fleetincense' is an anagram of 'LIFE SENTENCE'.

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(Other definitions for life sentence that I've seen before include "Maximum stretch?" , "Long prison stay" , "Long term of imprisonment" , "Very large bird" , "Judges may confirm such" .)

I've seen this clue in The Telegraph.

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