loonie, n.¹ — Green’s Dictionary of Slang

loonie n.¹

[the representation of a loon or diver on its reverse]

(Can.) the Can. $1 coin, introduced in 1987.

2001

2001		OnLine Dict. of Playground Sl. 🌐 loonie n. Canadian one-dollar coin, originated from the loon on the one side of it.
2001		Week (US) 8 June 13: Will the greenback kill the loonie?