no laughing matter

dangerous deep difficult far-reaching grievous important major meaningful severe significant tough urgent

arduous fateful fell formidable grave grim hard heavy laborious meaning business menacing momentous no joke of consequence operose out for blood playing hard ball pressing smoking sobering strenuous strictly business threatening ugly unamusing unhumorous worrying

calm easy facile friendly insignificant little meaningless minor small trivial unimportant worthless

flippant funny happy light unserious