unsustainable

comparative more unsustainable · superlative most unsustainable

1. Not sustainable.

   You don't have to be Einstein to work out that this level of government subsidy is unsustainable.

   2022 January 12, Sir Michael Holden, “Reform of the workforce or death by a thousand cuts?”, in RAIL, number 948, page 22

   1 more example

   RTDs cover a multitude of sips, including: “hard” or “spiked” teas, coffees, kombuchas and seltzers; […]. And although the sector was birthed in the ’30s by drinks like Campari Soda, and boomed in the ’90s with Bacardi Breezer and Smirnoff Ice, RTDs are now at a point of seemingly unsustainable saturation.

   2022 July 4, Ben Schott, “Is There Anything That Gen Z Won’t Drink?”, in The Washington Post

plural unsustainables

1. Something that cannot be sustained.