11-sided coin, informally Crossword Clue

 Yes, the informal name for the 11-sided coin in Canada is a "loonie". It is a one-dollar coin that was introduced in 1987. The coin features a loon, a type of bird, on the obverse side. The reverse side features the Canadian coat of arms.

The name "loonie" is a slang term that is thought to have originated in the early 1990s. It is a play on the word "loony", which is a slang term for someone who is crazy. The name "toonie" is used informally to refer to the two-dollar coin, which was introduced in 1996. This coin features a polar bear on the obverse side.

I hope this helps!