A Scottish term describing a person of shabby or, somewhat cruely, financially restricted appearance.
"Look at her, she's a right treg"
"Piss of you treg"
Treg is the pseudonim for the writer Gretchin Hardwold. If you notice, Treg is Gret backwards. Her books include:
"A wander through the Willow Trees"
"Crime and Perdition"