We found 33 dictionaries that define the word arachnid:

General (25 matching dictionaries)

1. arachnid: Merriam-Webster
2. arachnid: Oxford Learner's Dictionaries
3. arachnid: American Heritage Dictionary of the English Language
4. arachnid: Collins English Dictionary
5. arachnid: Vocabulary.com
6. Arachnid, arachnid: Wordnik
7. arachnid: Cambridge Advanced Learner's Dictionary
8. arachnid: Wiktionary
9. arachnid: Webster's New World College Dictionary, 4th Ed.
10. arachnid: The Wordsmyth English Dictionary-Thesaurus
11. arachnid: Infoplease Dictionary
12. arachnid: Dictionary.com
13. arachnid: Online Etymology Dictionary
14. Arachnid (disambiguation), Arachnid (film), Arachnid: Wikipedia, the Free Encyclopedia
15. Arachnid: Online Plain Text English Dictionary
16. arachnid: Webster's Revised Unabridged, 1913 Edition
17. arachnid: Rhymezone
18. Arachnid: AllWords.com Multi-Lingual Dictionary
19. arachnid: FreeDictionary.org
20. arachnid: Mnemonic Dictionary
21. arachnid: TheFreeDictionary.com
22. arachnid: Longman Dictionary of Contemporary English
23. arachnid: Merriam-Webster

Art (1 matching dictionary)

24. An Etymological Dictionary of Classical Mythology (No longer online)

Computing (1 matching dictionary)

25. arachnid: Encyclopedia

Medicine (4 matching dictionaries)

26. arachnid: Merriam-Webster Medical Dictionary
27. Dorland's Illustrated Medical Dictionary (No longer online)
28. online medical dictionary (No longer online)
29. arachnid: Medical dictionary

Miscellaneous (1 matching dictionary)

30. ARACHNID: Acronym Finder

Slang (1 matching dictionary)

31. arachnid: Urban Dictionary

(Note: See arachnids as well.)

Definitions from Wiktionary ( ) ▸ noun:  Any of the eight-legged creatures, including spiders, mites, and scorpions, of the class Arachnida. Similar: arachnoid, acarid, araneoid, arachnoidid, mite, arachnomorph, araneomorph, scorpion, acarus, anapid, more... Opposite: entomology Types: spider, scorpion, tick, mites, cricket, centipede, millipede, harvestman, more... Adjectives: other, giant, small, huge, tiny, hairy, marine, adult, primitive, only, peculiar Colors:     black,     brown,     gray,     tan,     beige, more... ▸ Word origin ▸ Words similar to arachnid ▸ Usage examples for arachnid ▸ Idioms related to arachnid ▸ Wikipedia articles (New!) ▸ Popular adjectives describing arachnid ▸ Words that often appear near arachnid ▸ Rhymes of arachnid ▸ Invented words related to arachnid