fall sick

fall sick (third-person singular simple present falls sick, present participle falling sick, simple past fell sick, past participle fallen sick)

1. To become ill; to fall ill.

• “fall sick”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• “fall sick”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.