Definition of in fits (of laughter) in US English:

in fits (of laughter)

phrase

informal
  • Highly amused.

    ‘he had us all in fits’
    • ‘The rest of us collapsed in fits of laughter at poor old Dave.’
    • ‘We collapsed in fits, the tutor had overheard and was almost wetting herself, and the 5 others were demanding to know what we'd said.’
    • ‘Eventually, after half an hour rolling around on the floor in fits of laughter, I managed to regain my composure.’
    • ‘Peter had one of the locals in fits of laughter when he was doing a line dance.’
    • ‘There was a time when circus was a popular form of entertainment - with acrobats and bold ring-masters to whose crack of the whip wild animals played awesome tricks and the clowns left packed audiences in fits.’
    • ‘At one point, she had the audience in fits.’
    • ‘Once we were out of harm's way, we all ended up breaking down in fits of uncontrollable laughter - partly to relieve the tension of the near-miss situation, but mostly because of the absurdity of what had just happened.’
    • ‘Both the staging and acting are universally superb and we were in fits of laughter throughout.’
    • ‘For starters, I was in fits of laughter at the sight of him, and his swearing and shouting just made me worse.’
    • ‘His quick wit and confident delivery had the audience in fits of laughter.’