In Delaunay’s Theorem on classification of surfaces of CMC there are ‘undulary’, ‘unduloid’, ‘nodary’, ‘nodoid’. But I don’t know why they are so called. I searched that ‘undulary’ and ‘undoloid’ have something to do with ‘wave’. However I couldn’t find out ‘nodary’ and ‘nodoid’. I am from China, and I wonder what roots these words are based on. I also wonder if somewhere I can look up mathematical terminologies and taste their meanings for a better understanding.

Any help will be appreciated.

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