Definition of have (got) something on the brain in US English:

have (got) something on the brain

phrase

informal
  • Be obsessed with something.

    ‘John has cars on the brain’
    • ‘I have a patient on the brain as well.’
    • ‘He had my children on the brain and made me feel like I was a total failure.’
    • ‘For most of my adult life I have had a tune on the brain.’
    • ‘Again I thought of Andreios, just a brief second, but the hair and appearance was again off (I really had guys on the brain, needed to get over this).’
    • ‘‘I have titrations on the brain,’ I gasped, nosily sucking in air.’
    • ‘Or at least acknowledge that they have it on the brain as much as men do.’
    • ‘I've had interviews on the brain for the past few months - verbal ones, written ones, for business and for pleasure.’
    • ‘Peers and MPs had trains on the brain this week: the beloved Flying Scotsman, its clapped-out modern day equivalents which are, apparently, too small for fat people and those with broken-down loos.’
    • ‘I have taken to shuffling about on the carpet with my rubber-soled shoes, distributing electric shocks because unlike the boys I don't have balls on the brain and rolling mouse balls along the carpet at a pin just doesn't interest me.’
    • ‘The Core Team, as you probably know, has babies on the brain.’
    be fixated, be preoccupied, be infatuated, be possessed, be haunted, be consumed, be plagued, be tormented, be bedevilled, be eaten up, be gripped, be in the grip of, be dominated, be beset
    View synonyms