On the way, they interrupted critical ongoing business (5)
I believe the answer is:
along
'on the way' is the definition.
(I've seen this in another clue)
'they interrupted critical ongoing business' is the wordplay.
'ALONG' is hidden within the letters.
However, I'm uncertain how this is indicated.
Can you help me to learn more?
(Other definitions for along that I've seen before include "Forward - in a line" , "Lining" , "For the length of" , "From one end to the other" , "Lengthwise" .)