We found 27 dictionaries that define the word hardpan:

General (19 matching dictionaries)

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

Business (1 matching dictionary)

20. Construction Term Glossary (No longer online)

Computing (1 matching dictionary)

21. hardpan: Encyclopedia

Medicine (1 matching dictionary)

22. online medical dictionary (No longer online)

Science (2 matching dictionaries)

23. Botanical Terms (No longer online)
24. Illustrated Glossary of Geologic Terms (No longer online)

Tech (3 matching dictionaries)

25. Glossary of Meteorology (No longer online)
26. Lake and Water Word Glossary (No longer online)
27. Glossary of Water Resource Terms (No longer online)

(Note: See hardpans as well.)

Definitions from Wiktionary (hardpan) ▸ noun:  A distinct layer of soil that is largely impervious to water. ▸ noun:  Synonym of dry lake. Similar: caliche, duripan, hardground, claypan, hardrock, ortstein, stonelayer, inceptisol, aquand, aquifer, more... Opposite: loose soil, soft soil, friable soil Types: claypan, caliche, ironpan, petrocalcic, petrogypsic, petroplinthic, petrosalic, petroferric, more... Adjectives: impervious, calcareous, brown, underlying, true, compacted, impermeable, red, artificial, shallow, siliceous ▸ Words similar to hardpan ▸ Usage examples for hardpan ▸ Idioms related to hardpan ▸ Wikipedia articles (New!) ▸ Popular adjectives describing hardpan ▸ Words that often appear near hardpan ▸ Rhymes of hardpan ▸ Invented words related to hardpan