put it mildly

put it mildly (third-person singular simple present puts it mildly, present participle putting it mildly, simple past and past participle put it mildly)

1. To state without exaggeration; to understate, to state in euphemistic terms.

   to put it mildly

   That's putting it mildly!

   • 2023 March 5, Phil McNulty, “Liverpool 7-0 Manchester United”, in BBC Sport‎:

     His players responded. Wolverhampton Wanderers were beaten at Anfield and United, to put it mildly, outclassed.

• to put it another way
• not to put too fine a point on it

• “to put it mildly”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• “to put it mildly” in Longman Dictionary of Contemporary English, Longman.
• “to put it mildly”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.