Almost a disaster, messing up sir’s name (4,4)
I believe the answer is:
near miss
'almost' is the definition.
(I've seen this in another clue)
'up sir's name' is the wordplay.
'up' indicates anagramming the letters (letters get chucked up).
'sirs'+'name'='sirsname'
'sirsname' is an anagram of 'NEAR MISS'.
'a disaster messing' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for near miss that I've seen before include "narrowly averted disaster" , "Failure just" , "reason for alarm or relief on aircraft?" , "almost getting killed?" , "A narrowly avoided collision in seminars" .)