understate

verb3

1. •
   To state (something) with less completeness than needed; to minimise or downplay.

   • To call this decision a calculated bet understates the risk; it is a Hail Mary pass.
2. •
   To state a quantity that is too low.

   • The company had been understating its liabilities for years.
3. •
   To state (something) with an intentional lack of emphasis, in order to express irony.

   • She is the queen of understatement: she understated her critique masterfully.