The most frequent usage I make of the Kindle dictionary is to look up the British (sometimes also Canadian) usage of English words. These may or may not be archaic.
I cannot always pick up the meaning in context. I often read 19th and 20th century British authors and am a born and bred American, so that explains my ignorance.
This morning I looked up serviette, which we call napkin.
An American writer that has sent me to the dictionary this year is Ed McBain. He had a rich vocabulary which he used to paint vivid descriptions.
Dean