desiderium

Desiderium, desiderii, n., second declension, from desidero. It takes an objective genitive: desiderium patriae, longing for home, not longing belonging to home.

The classical weight of the word is absence. You feel desiderium for what has gone: a dead friend, a lost country, an army that did not come back, and Cicero uses it close to grief. It is not appetite. The ecclesiastical corpus keeps the yearning but points it upward, and then in the plural turns it the other way entirely, so desideria carnis are the appetites you are meant to be fighting. Singular reaches for something good, plural usually does not.