grim

Etymology 1

From Middle English grim, from Old English grimm, from Proto-West Germanic *grimm, from Proto-Germanic *grimmaz, from Proto-Indo-European *gʰrem- (“to resound, thunder, grumble, roar”).

adj

1. Dismal and gloomy, cold and forbidding.
   Life was grim in many northern industrial towns.
   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. August 30, 2019, 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. January 12 2022, Nigel Harris, “Comment: Unhappy start to 2022”, in RAIL, number 948, page 3
2. Rigid and unrelenting.
   His grim determination enabled him to win.
3. Ghastly or sinister.
   A grim castle overshadowed the village.
   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
4. Disgusting; gross.
   – Wanna see the dead rat I found in my fridge? – Mate, that is grim!
5. (obsolete) Fierce, cruel, furious.

verb

1. (transitive, rare) To make grim; to give a stern or forbidding aspect to.

noun

1. (MLE, slang, probably a fashionable word around 2006, now dated) A promiscuous woman.
   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 2006-07-01, “Grim” (track 8), in Wiley (lyrics), Eskiboy: Da 2nd Phaze

Etymology 2

From Middle English grim, grym, greme, from Old English *grimu, *grimmu, grima, from Proto-Germanic *grimmį̄ (“anger, wrath”), from Proto-Indo-European *gʰrem- (“to resound, thunder, grumble, roar”). Cognate with Middle Dutch grimme, Middle High German grimme f (“anger”), modern German Grimm m.

noun

1. (obsolete) Anger, wrath.
2. (obsolete) A specter, ghost, haunting spirit.