Definition of "Grim" :

adjective: shockingly repellent; inspiring horror

"The grim aftermath of the bombing."

adjective: causing dejection

"Grim rainy weather."

adjective: filled with melancholy and despondency

"Took a grim view of the economy."

adjective: not to be placated or appeased or moved by entreaty

"Grim determination."

adjective: harshly uninviting or formidable in manner or appearance

"A grim man loving duty more than humanity."

adjective: harshly ironic or sinister

"A grim joke."