A desideratum is something people want or feel they need — usually an ideal, a missing piece, a condition they are aiming at, not a snack they fancy this afternoon. Scholars, officials, and careful writers use it; almost nobody says it in the street. One such wish is a desideratum; more than one are desiderata, keeping the Latin plural. Though actually, the word often sounds a little grand, as if the speaker is naming a high goal rather than a shopping list. It names the thing wanted, not the feeling of wanting. English borrowed the learned Latin form rather than building this sense from everyday desire.

渴望得到之物、理想條件（很書面；日常不會這麼說）