We found 23 dictionaries that define the word hard-on:

General (18 matching dictionaries)

1. hard-on: Merriam-Webster
2. hard-on: Oxford Learner's Dictionaries
3. hard-on: American Heritage Dictionary of the English Language
4. hard-on, hard-on: Collins English Dictionary
5. hard-on: Vocabulary.com
6. hard-on: Wordnik
7. hard-on: Cambridge Advanced Learner's Dictionary
8. hard-on: Wiktionary
9. hard-on: Webster's New World College Dictionary, 4th Ed.
10. hard-on: The Wordsmyth English Dictionary-Thesaurus
11. hard-on: Infoplease Dictionary
12. hard-on: Dictionary.com
13. hard-on: Rhymezone
14. hard-on: FreeDictionary.org
15. hard-on: Mnemonic Dictionary
16. hard-on: TheFreeDictionary.com

Business (1 matching dictionary)

17. hard-on: Legal dictionary

Computing (1 matching dictionary)

18. hard-on: Encyclopedia

Medicine (1 matching dictionary)

19. hard-on: Medical dictionary

Slang (2 matching dictionaries)

20. hard-on, hard-on: Green’s Dictionary of Slang
21. hard-on: English slang and colloquialisms used in the United Kingdom

(Note: See hard-ons as well.)

Definitions from Wiktionary ( ) ▸ noun:  (slang, vulgar) An erection of the penis. ▸ noun:  (slang, vulgar, figurative) A desirous arousal based on a fascination or obsession. Similar: erection, Hardon, hard on, horn, head, warhead, hard, horsecock, hardhat, hate boner, more... Opposite: soft, flaccid, limp ▸ Words similar to hard-on ▸ Usage examples for hard-on ▸ Idioms related to hard-on ▸ Wikipedia articles (New!) ▸ Popular adjectives describing hard-on ▸ Words that often appear near hard-on ▸ Rhymes of hard-on ▸ Invented words related to hard-on