Santonicas is not a common word in English. It seems like it might be a made-up word or a very rare word that is not used often.
Because it is not a common word, people might not understand what it means.
Examples:
I have never heard the word santonicas before.
The book I'm reading doesn't have the word santonicas in it.
Do you know what santonicas means?
I think I just made up the word santonicas!
Santonicas is a strange word that no one knows.
I tried to use santonicas in a sentence, but it didn't make sense.