Quizzes, tests, exercises and puzzles for English as a Second Language (ESL), English as a foreign language (EFL), Teaching EFL (TEFL), Test of EFL (TOEFL), English for speakers of other languages (ESOL), Teaching ESOL (TESOL), TOEIC.
Google can be used as an online dictionary. To look up a word, type in the keyword "define:" followed by the term you're looking for (i.e. "define:search engine"). The pages are populated with the search results.