We found 40 dictionaries that define the word aggression:

General (26 matching dictionaries)

1. aggression: Merriam-Webster
2. aggression: Oxford Learner's Dictionaries
3. aggression: American Heritage Dictionary of the English Language
4. aggression: Collins English Dictionary
5. aggression: Vocabulary.com
6. Aggression, aggression: Wordnik
7. aggression: Cambridge Advanced Learner's Dictionary
8. aggression: Wiktionary
9. aggression: Webster's New World College Dictionary, 4th Ed.
10. aggression: The Wordsmyth English Dictionary-Thesaurus
11. aggression: Infoplease Dictionary
12. aggression: Dictionary.com
13. aggression: Online Etymology Dictionary
14. aggression: Cambridge Essential American English Dictionary
15. Aggression (disambiguation), Aggression (poker), Aggression (psychology), Aggression (war crime), Aggression, The Aggression: Wikipedia, the Free Encyclopedia
16. Aggression: Online Plain Text English Dictionary
17. aggression: Rhymezone
18. Aggression (f), aggression: AllWords.com Multi-Lingual Dictionary
19. aggression: Webster's 1828 Dictionary
20. aggression: FreeDictionary.org
21. aggression: Mnemonic Dictionary
22. aggression: TheFreeDictionary.com
23. aggression: Longman Dictionary of Contemporary English
24. aggression: Merriam-Webster

Business (3 matching dictionaries)

25. Aggression (psychology), aggression: Legal dictionary
26. aggression: Financial dictionary
27. BusinessDictionary.com (No longer online)

Computing (1 matching dictionary)

28. Aggression (psychology), aggression: Encyclopedia

Medicine (5 matching dictionaries)

29. aggression: Merriam-Webster Medical Dictionary
30. Medical Dictionary (No longer online)
31. online medical dictionary (No longer online)
32. Specific Diseases/Disorders (No longer online)
33. Aggression (psychology), aggression: Medical dictionary

Miscellaneous (2 matching dictionaries)

34. Political (No longer online)
35. Brilliant Dream Dictionary (No longer online)

Science (1 matching dictionary)

36. aggression: Anthropological Terms

Slang (1 matching dictionary)

37. Aggression: Urban Dictionary

Sports (1 matching dictionary)

38. Aggression: Sports Definitions

(Note: See aggressions as well.)

Definitions from Wiktionary ( ) ▸ noun:  The act of initiating hostilities or invasion. ▸ noun:  The practice or habit of launching attacks. ▸ noun:  Hostile or destructive behavior or actions. ▸ noun:  (libertarianism) The initiation or threat of conflict; coercion. Similar: aggressiveness, hostility, agression, belligerence, violence, pugnacity, provocation, assertiveness, bellicosity, agressiveness, more... Opposite: peacefulness, passivity, gentleness, calmness, docility Types: verbal, physical, psychological, passive-aggressive, indirect, more... Phrases: passive aggression, territorial aggression, maternal aggression, predatory aggression, parental aggression, more... Adjectives: physical, non, japanese, sexual, foreign, external, communist, german, verbal, military, soviet Colors:     red,     black,     dark red,     maroon,     crimson, more... ▸ Word origin ▸ Words similar to aggression ▸ Usage examples for aggression ▸ Idioms related to aggression ▸ Wikipedia articles (New!) ▸ Popular adjectives describing aggression ▸ Words that often appear near aggression ▸ Rhymes of aggression ▸ Invented words related to aggression