The second letter in the final word is an 'e', the shape is the same as in all other words a,d the letter after it looks very much like an 'f' so Totally De(a)f.
As he was an army pensioner his deafness could have been the result of a head injury of burst ear drums, both of which could have contributed to his death.
Might be worth getting a £7 email PDF copy of his death certificate direct from the GRO.