cura

Cura, curae, f., first declension. One word spanning anxious worry, careful attention and formal responsibility for something, and the third is the one readers miss: cura urbis is a magistrate's remit, not his nerves. Take a genitive for the thing cared for, cura rerum divinarum.

The verb curo is worth learning alongside it, because with a gerundive it is the standard way of saying you had something done rather than did it yourself: pontem faciendum curavit, "he had a bridge built". The medical sense arrived late and is not the Latin centre of gravity: a Roman cura is the tending, not the recovery. English cure, curate, curious, secure and accurate all descend from it.