Are grave, gravy, and gravity related? Though they could be interpreted to have associated senses, their etymological origins are distinct.
The noun grave, referring to a burial place, may seem to refer to weight, but it is unrelated to gravy or gravity, as is its derivative engrave. Grave and engrave stem from the Old English term grafen, meaning “dig” or “chisel”; the latter word, describing the action of inscription in stone or another hard surface, is a later form of the obsolete verb grave, which meant “carve.”
And though gravy, a sauce based on the juice of cooked meat, can be heavy, its French forebear, grave (also graue), is apparently a misspelling of graune, meaning “sauce” or “stew”; its origin is the Latin word granum, meaning “grain” or “seed.” (Gravy can also mean, by extension, something good that was not earned or expected, such as effortlessly acquired funds, hence the idiom “gravy train” for a source of easy money.) Meanwhile, gravel comes from the Old French word gravele, which pertains to sand or small stones.
But gravity is weighed down by a family of words, a couple of them perhaps unexpected, that have as a common ancestor gravis, meaning “heavy.” One of them is the sister noun gravitation; the sense distinction is that gravity refers to weight or to downward acceleration, which consists of centrifugal and gravitational, or attracting, forces. The verb form gravitate has a scientific meaning of “exert weight” or “move downward” but has also acquired the sense of emotional attraction or philosophical tendency; one might be said to gravitate toward a certain personality type or a specific school of thought.
Other terms include the adjective grave, meaning “solemn,” gravid, meaning “pregnant” (from the notion of the pregnant state as a heavy burden), and gravitas, which means “dignity,” “influence,” or “presence” and alludes to a person’s serious attitude or physical bearing.
Two words whose kinship with these words and each other may not be apparent are aggravation and grief. The original meaning of aggravation is “the act or result of making something worse.” It has another sense, “irritation,” which dilutes the useful specificity of the earlier definition but is also hundreds of years old.
Grief, meanwhile, is also descended from gravis. Its meaning, “suffering,” stems from an Old French word (spelled the same) meaning “injustice” or “misfortune.” One who experiences grief is said to grieve, although the term can also apply to anger or oppression, especially in the verb form aggrieve, and one who is aggrieved is said to have a grievance. (That word may also apply to a statement articulating one’s dissatisfaction.) The adjectival form, grievous, means “difficult” or “serious.” Meanwhile, the term gravamen refers to the gist, or focus, of a grievance, especially in legal contexts, in which it pertains to the grounds for a legal action.