I think this word means: A great storm at sea, sometimes/always involving a big whirlpool that eats pirate ships.  Yarrh!

Actual definition:  \MAYL-struhm, noun:

1. A large, powerful, or destructive whirlpool.
2. Something resembling a maelstrom; a violent, disordered, or turbulent state of affairs.

Remark: Sweet!