Grievous means very serious, and causing great suffering. Grievous harm, a grievous loss, grievous bodily harm.
It is formal and heavy, and in England and Wales grievous bodily harm is a specific offence, usually shortened to GBH. Outside law it is used of losses and errors: a grievous mistake, a grievous blow. Note the pronunciation — two syllables, not three, so grievous rather than grievious, which is a very common slip. Note grievance, grieve.
1adjectivegrievousVery serious, and causing great suffering.
“Losing their only son was a grievous blow to the family.”
synonyms: severe, grave
grievous is a quality of seriousness.
Anglo-Norman grevous comes from Latin gravare, to burden, from gravis, heavy. Grave, gravity and aggravate come from the same weight.
Proto-Indo-European
*gʷreh₂-
Latin
gravō — to burden
Old French
grever
Anglo-Norman
grevous
Middle English
grevous
English, today
grievous
From Middle English grevous, from Anglo-Norman grevous, from Old French grever, from Latin gravō (“to burden”). Developed in the 13th century. Equivalent to grief + ous.
Etymology from Wiktionary, CC BY-SA