`Rideau` which means curtain in the French language is a popular name for geographical features and organizations in the Ottawa, Canada area. The early French used `Rideau` when naming the Rideau Falls because of their similarity to a curtain. Places in the Ottawa area named Rideau: Other: ...[company] Rideau (oʊ {respell|REE|doh}; ʁido) is a private, Canada-based company that provides corporate and governmental recognition programs and products. Founded in 1912 as the Stephenson Company, the company has undergone several buyouts and ventures in different geographical markets. Rideau was the first Canadian company to produce t...
ridge or mound of earth used for defense
• (n.) A small mound of earth; ground slightly elevated; a small ridge.
Ri·deau' (re*dō') noun [ French] A small mound of earth; ground slightly elevated; a small ridge. 
Rideau is a cultivated variety of potato.