百度汉语:
词典:
Top 5 monolingual Learner's Dictionaries are
1. **** Cambridge Dictionary http://dictionary.cambridge.org/
2. Longman Dictionary http://www.ldoceonline.com/
3. Oxford Collocations Dictionary http://www.ozdic.com/
4. Thesaurus.com http://www.thesaurus.com/
5. Oxford Dictionaries https://en.oxforddictionaries.com/
6. **** M-W http://learnersdictionary.com/
7. ****Chinese-English https://cn.bing.com/dict/
8. ****Chinese-English http://dict.cn/
http://www.freecollocation.com/