Large crowd taking time out from trade (4)

I believe the answer is:

ruck

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

'large crowd' is the definition.
'ruck' can be an answer for 'crowd' (ruck can mean a crowd of people). I am unsure of the 'large' bit.

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for ruck that I've seen before include "Loose scrummage" , "Indistinguishable heap - a loose 10" , "Cower" , "Rugby scrum or crease in dress" , "Undistinguished crowd - irregular crease" .)

I've seen this clue in The Irish Times.

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