From Wiktionary, the free dictionary
Deverbal from put in
put -in plural put-ins
( rugby ) scrum ; the right to do this
2005 June 30, Designated Members of the Rugby Committee, Clarification 3 2005 , World Rugby:
The abovementioned scenario is illegal, and the referee would order a scrum at the place of the original penalty, with the put in to the black team. 2013 September 30, Brian Moore, “Crooked put-ins make scrums a test of brute strength ”, in The Daily Telegraph :The whole point of the laws as drawn is to make the scrum a contest whereby the put-in side has the advantage of timing the feed and having its hooker closer to the ball.
