If something is copious, there a lot of it. If you take copious notes you'll do well when it comes time for review sessions — unless you can't read your handwriting.
Copious comes from the Latin copia, or abundance. It is generally used for things we think are good, like a copious harvest, or a copious rainfall. You can use copious for something numeric, like your copious admirers, or for something qualitative, like your their copious admiration. Some synonyms are plentiful, abundant, bountiful, generous, ample.
