Synonyms of grievous

1 Syllable

ter, sharp, sad, dire, great, tough

2 Syllables

harmful, heinous, monstrous, nagging, wounding, dreadful, tragic, greatest, dismal, mournful, grave, glaring, piteous, woeful, shocking, flagrant, painful, beefing, ruthful, smarting, weighty, hurtful, mortal, heavy, taxing, unfair, galling, dolent

3 Syllables

pitiful, demanding, outrageous, disturbing, injurious, disquieting, heartbreaking, damaging, onerous, atrocious, sobering, pitiable, villainous, shameful, plaintive, death-dealing, unsporting, backbreaker, afflicting, upsetting, heightened, dolorous, heart-rending, pathetic, appalling, exacting, egregious, distressing, sorrowful, godawful

4 Syllables

lamentable, deplorable, troublesome, calamitous, unamusing, oppressive, dolesome, dolorific, depressive, unbearable, offensive, agonizing, distasteful, regrettable

5 Syllables

superincumbent, intolerable, uncomfortable