Obese Bert bringing about demise (5)

I believe the answer is:

fatal

'bringing about demise' is the definition.

'obese bert' is the wordplay.
'obese' becomes 'fat' ('fat' can be similar in meaning to 'obese').
'bert' becomes 'al' (both are short for Albert).
'fat'+'al'='FATAL'

(Other definitions for fatal that I've seen before include "Bringing ruin" , "Mortal" , "Causing or leading up to death" , "Causing death, say accident" , "Involving death" .)

I've seen this clue in The Guardian.

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