Clubs criminals were sometimes clapped in? (5)

I believe the answer is:

irons

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

'clubs' is the definition.
(iron is a kind of club)

I don't understand the rest of the clue.

(Other definitions for irons that I've seen before include "British actor" , "English player" , "Presses clothes" , "Metal-headed golfclubs" , "for old convict to wear" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app