A brief notice that appears, says one thing, and leaves on its own. It asks no answer and blocks nothing.
Latin tostus (parched, roasted), the past participle of torrere (to burn, to scorch); a drink offered to someone's health took its name from spiced bread once floated in the cup, and a software notice later borrowed that same image of something raised for a moment and gone.
A brief notice that appears, says one thing, and leaves on its own. It asks no answer and blocks nothing, the way a toast is raised and then set back down.