Definition of "grim"

Cristiana Paşca Palmer, the executive secretary of the UN Convention on Biological Diversity, said the destruction of the world’s biggest rainforest was a grim reminder that a fresh approach needed to stabilise the climate and prevent ecosystems from declining to a point of no return, with dire consequences for humanity.

2019 August 30, Jonathan Watts, “Amazon fires show world heading for point of no return, says UN”, in The Guardian‎

It's been a grim start to the year.

2022 January 12, Nigel Harris, “Comment: Unhappy start to 2022”, in RAIL, number 948, page 3

In movie terms, it suggests Paul Verhoeven in Robocop/Starship Troopers mode, an R-rated bloodbath where the grim spectacle of children murdering each other on television is bread-and-circuses for the age of reality TV, enforced by a totalitarian regime to keep the masses at bay.

2012 March 22, Scott Tobias, “The Hunger Games”, in AV Club

Whenever I find myself growing grim about the mouth; whenever it is a damp, drizzly November in my soul; whenever I find myself involuntarily pausing before coffin warehouses, and bringing up the rear of every funeral I meet;

1851 November 14, Herman Melville, chapter 1, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, page 1

You got a new girl and she looks choong (Choong)But you didn't know your girl was a grim[…]Your girl she's a grim, I wouldn't have no grim as my ting

2006 July 1, “Grim” (track 8), in Wiley (lyrics), Eskiboy: Da 2nd Phaze‎