We found 16 dictionaries that define the word hallucinogens:

General (10 matching dictionaries)

1. hallucinogens: Merriam-Webster
2. hallucinogens: Collins English Dictionary
3. hallucinogens: Vocabulary.com
4. Hallucinogens, hallucinogens: Wordnik
5. hallucinogens: Cambridge Advanced Learner's Dictionary
6. hallucinogens: Wiktionary
7. hallucinogens: Dictionary.com
8. hallucinogens: Cambridge Essential American English Dictionary
9. Hallucinogens: Wikipedia, the Free Encyclopedia
10. Hallucinogens: TheFreeDictionary.com

Computing (1 matching dictionary)

11. Hallucinogens: Encyclopedia

Medicine (5 matching dictionaries)

12. hallucinogens: Merriam-Webster Medical Dictionary
13. Medical Dictionary (No longer online)
14. Hallucinogens: Merck Manuals
15. online medical dictionary (No longer online)
16. Hallucinogens: Medical dictionary

(Note: See hallucinogen as well.)

Definitions from Wiktionary (hallucinogen) ▸ noun:  Any substance tending to induce hallucination. ▸ Also see hallucinogen Opposite: stimulants, depressants, sedatives ▸ Words similar to hallucinogens ▸ Usage examples for hallucinogens ▸ Idioms related to hallucinogens ▸ Wikipedia articles (New!) ▸ Popular adjectives describing hallucinogens ▸ Words that often appear near hallucinogens ▸ Rhymes of hallucinogens ▸ Invented words related to hallucinogens