fast on
adj.— «If I know I’ve got to be up early, I normally can’t sleep too well, but that night I was, as they say round they these parts, “fast on.” I was “fast on” and having a dream.» —“Alarming tale that gave me a wake-up call” by Ian McMillan Yorkshire Post (Leeds, United Kingdom) Jan. 29, 2008. (source: Double-Tongued Dictionary)
Further reading
An old Irish curse goes: May the devil make a ladder of your backbones while picking apples in the garden of hell. If you’d rather offer someone a friendlier wish, try May angels bless your sleep with the smell of apple pies. This is part of a...
A French idiom that means “to sleep in” or “lie around lazily in bed after waking” is faire la grasse matinée, literally to “make the fat morning.” If you fall in love easily, you’re said to have un coeur...