graco

One letter apart, and two different roots. Graco is this page. Gracia, at rank 1,803, is graceful, elegant in movement. They look like an adjective and its noun and they are not: the dictionaries list them as separate roots, grac/o and graci/a, and the noun of gracia is gracio or gracieco, not graco. So graco and gracio differ by an i, mean unrelated things, and both are real words. This is the fence, and the point of the fence is that you cannot get over it by reasoning. You have to know it.

What graco means. It is a theological term: the unearned help or favour God gives a person, the sense in the phrase by the grace of God and in the hymn Amazing Grace. The reference dictionaries define it that way and every citation they give is from scripture or from religious writing. It is not aesthetic grace, not social graciousness, not a grace period, and not the grace said before a meal (that is tablopreĝo or simply preĝo). If you want any of those, graco is the wrong word.

And what gracia means. Beautiful through easy, harmonious movement, or through well-proportioned form. A dancer is gracia. A cat crossing a wall is gracia. A line of poetry can be. Malgracia is the opposite, clumsy or ungainly, and it is a genuinely useful word. Note the shared Latin ancestry is arguable but the Esperanto behaviour is not: the two roots do not derive from each other inside the language, and treating graco as the noun of gracia will produce sentences that a reader takes theologically when you meant a compliment.

Alternatives, when you want to be plainer. For God's favour towards people, difavoro says the same thing out of Esperanto's own pieces (di- plus favoro) and is clearer to a reader with no church background. For divine help asked for and given, dihelpo. The reference works themselves recommend those substitutions where the context allows, which is a nice illustration of the language's habit of offering a built word alongside a borrowed one. Graca is the adjective, and pergraca turns up in older devotional prose.