Met ringleader with article on Irish trade union (3,4)
I believe the answer is:
ran into
'met' is the definition.
(I've seen this in another clue)
'ringleader with article on irish trade union' is the wordplay.
'ringleader' becomes 'r' (first letter of ring).
'with' means one lot of letters go next to another.
'article' becomes 'an' (English indefinite article).
'on irish trade union' becomes 'into' (I am not sure about this - if you are sure you should believe this answer much more).
'r'+'an'+'into'='RAN INTO'
Can you help me to learn more?
(Other definitions for ran into that I've seen before include "Met - in a collision?" , "Encountered" , "Came across" , "saw by accident" .)