Crossword Genius

Foul lads go berserk in a joint abruptly (3,2,1,6)

Ross

I believe the answer is:

all of a sudden

I'm a little stuck... Click here to teach me more about this clue!

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

'foul lads go berserk in a joint' is the wordplay.
'go berserk' indicates anagramming the letters.
'in' is an insertion indicator.
'a joint' becomes 'aden' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'foul'+'lads'='foullads'
'foullads' with letters rearranged gives 'llofasud'.
'llofasud' inserted within 'aden' is 'ALL OF A SUDDEN'.

Can you help me to learn more?

(Other definitions for all of a sudden that I've seen before include "abruptly" , "Quickly and unexpectedly" , "In an unexpected manner" , "Without warning" .)

I've seen this clue in The Hindu.
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