Gravest meaning : To dig. To carve or cut, as letters or figures, on some hard substance; to engrave. To carve out or give shape to, by cutting with a chisel; to sculpture. To impress deeply (on the mind); to fix indelibly. To entomb; to bury. To write or delineate on hard substances, by means of incised lines; to practice engraving. Characterised by a dignified sense of seriousness; not cheerful. Low in pitch, tone etc. Serious, in a negative sense; important, formidable. Influential, important; authoritative. To clean, as a vessel's bottom, of barnacles, grass, etc., and pay it over with pitch — so called because graves or greaves was formerly used for this purpose.