Definition of do something in in English:

do something in

phrasal verb

informal
  • Injure something.

    ‘I did my back in a few years ago’
    • ‘In March of that year, I did my back in, and for the first time in my life I realised what it meant to be housebound.’
    • ‘I did my ankle in on the second day and had to go home early.’
    • ‘I know my dad hated not working when he did his shoulder in.’
    • ‘She did her knee in about 3 years ago playing tennis.’
    injure, hurt, damage, maim, cripple, disable, paralyse