We found 28 dictionaries that define the word heartwood:

General (20 matching dictionaries)

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

Art (1 matching dictionary)

21. heartwood: ArtLex Lexicon of Visual Art Terminology

Business (1 matching dictionary)

22. Construction Term Glossary (No longer online)

Computing (1 matching dictionary)

23. heartwood: Encyclopedia

Medicine (1 matching dictionary)

24. online medical dictionary (No longer online)

Science (2 matching dictionaries)

25. Botanical Terms (No longer online)
26. On-Line Biology Book: GLOSSARY (No longer online)

Tech (2 matching dictionaries)

27. Heartwood: Glossary of Woodworking Terms
28. Sweetwater Music (No longer online)

Definitions from Wiktionary (heartwood) ▸ noun:  The wood nearer the heart of a stem or branch, different in color from the sapwood. Similar: duramen, sapwood, sap-wood, stemwood, heart pine, branchwood, spine, springwood, fruitwood, alburnum, more... Opposite: sapwood, outerwood, softwood Types: sapwood, more... Adjectives: brown, red, dark, colored, black, reddish, coloured, dead, durable, light, distinct ▸ Words similar to heartwood ▸ Usage examples for heartwood ▸ Idioms related to heartwood ▸ Wikipedia articles (New!) ▸ Popular adjectives describing heartwood ▸ Words that often appear near heartwood ▸ Rhymes of heartwood ▸ Invented words related to heartwood