Fitting a thing to the culture that will meet it, beyond translating its words. Meaning made at home rather than merely legible.
Latin cultura (cultivation, tending), from colere (to till, cultivate, tend); fitting a thing to the culture that will meet it, beyond merely translating its words into another tongue.
It shares culture's own root of tending rather than declaring, applied outward: the fitting is a cultivation done to a thing so it grows naturally in soil it was not made in. Legible only means the words survived the crossing; this is the harder claim, that the meaning did too.