Wigs on the green refers to a fight, brawl or fracas, or to a difference of
opinion that could lead to fisticuffs. It often appears as “there’ll be wigs on the green”, as a warning (or a prediction) that an altercation is likely to occur.
It is originally
Irish,
dating from the eighteenth century, when men usually wore wigs. If a fight started, the first thing that happened was that the wigs of those involved would be knocked off and would roll incongruously about on the
grass, to the amusement of bystanders and the embarrassment of participants.
It has fallen out of use in modern times but continues to be used by intellectuals especially in Ireland.