Is there a standard format for English vocabulary lists and some data sources in that format? (For example a standard XML)
For example SAT vocabulary or Basic English words, including definition, examples, phonetic,... in that format.
2 Answers
XDXF is an open source "XML Dictionary Exchange Format".
XDXF stands for XML Dictionary Exchange Format, and specifies a semantic format for storing dictionaries.
The main distinction of XDXF that makes it stand out among all other dictionary formats is that it doesn't contain almost any representational information about how articles should look like. Instead, XDXF stores only structural and semantic information in word articles. The choice of how they have to be rendered is shifted to dictionary-browsing software ("DS"), its settings and user preferences.
You could try out Merriam-Webster's Dictionary API, which has a basic XML standard for dictionary entries: http://www.dictionaryapi.com/products/api-collegiate-dictionary.htm
