Definition of nauseousness in US English:

nauseousness

noun

  • See nauseous

    • ‘The thought scared me to the point of nauseousness.’
    • ‘Seeing the open gates, I fought the feelings of déjà vu and nervous nauseousness that were rising in my chest.’
    • ‘She had a sudden urge to puke and the rashness in Derek's driving added to her nauseousness.’