Grievous

The adjective grievous is best pronounced with two syllables - 'GREE-ves', IPA: /ˈgriː vəs/. The adverb grievously likewise has only three syllables, 'GREEV-es-ly', IPA: /ˈgriː vəs lɪ/. Academics will tend to sneer at you if you use the common pronunciation with an extra syllable, 'GREEV-i-es' (IPA: /ˈgriː vɪ əs/) and 'GREEV-i-es-ly' (IPA: /ˈgriː vɪ əs lɪ/). Such a speech habit is said to be 'uneducated'.

Compare mischievous.

AWE has a note on the verb 'to grieve' at Greaves - grieves, which can apply, mutatis mutandis, to the adjective grievous. One common use of grievous at present is in the legal offence of '[assault causing] grievous bodily harm', or GBH. This is the most serious form of assault recognized under English law; there is a less serious offence of '[Assault occasioning] actual bodily harm', or ABH.