What does "sine" mean?

I see the suffix "sine" (seen/sin) a lot, adenosine, cytosine, lysine, tyrosine, etc. Most of where I hear it is in amino acid R groups, but it's usually only the prefix that is recognized as significant. 




According to [Textbook of metabolism and metabolic disorders](https://books.google.com/books?id=4M9qAAAAMAAJ&q=%22suffix%20osine%22&dq=%22suffix%20osine%22&hl=en&sa=X&ved=0ahUKEwiA5oGcpYXZAhWBwVkKHUrqDmcQ6AEIKTAA) (1964): 



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> The ribosides derived from purines have the suffix -osine; those from pyrimidines, the suffix -idine. The corresponding deoxyribosides, with the exception of thymidine, do not have any such simple designation. Occasionally, instead of, for example, guanine-deoxyriboside, the term deoxy-guanosine is used. 
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Beyond the more common adenosine and guanosine, there are also: 


[inosine](https://pubchem.ncbi.nlm.nih.gov/compound/inosine#section=Top) and 


[xanthosine](https://pubchem.ncbi.nlm.nih.gov/compound/xanthosine#section=Top)


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