What it means
A Scots way to say someone looks pale, washed out, and a bit not-right. You'd use it for illness, cold, tiredness, or that ghostly hungover face after a daft night. It usually lands half caring, half taking the mick, the kind of word that comes with sit down, hen, and have a cuppa.
Usage examples
"You’re looking pure peely-wally, hen. Big night, was it? Get yersel a cuppa and sit doon afore you topple in the close."
"You're looking awful peely-wally this morning, are you coming down with something?"
"After the flight she was pure peely-wally, straight to bed with a cuppa."
"Och, look at you, pure peely-wally after that bug. Get under a blanket and stop pretending you're grand."
"He came into work all peely-wally, eyes half-shut and skin like he'd been charged by moonlight instead of sleep."
Where it comes from
It’s a real Scots dialect word going back to older Scots use. Peely means pale or wan-looking, and wally here is part of the rhyming, sing-song build that gives it its droopy little music. The whole thing stuck because it sounds exactly like the look it describes, all drained colour and no sparkle.