We found 20 dictionaries that define the word tunnelling:

General (13 matching dictionaries)

1. tunnelling: Merriam-Webster
2. tunnelling: Oxford Learner's Dictionaries
3. tunnelling: Collins English Dictionary
4. tunnelling: Vocabulary.com
5. Tunnelling, tunnelling: Wordnik
6. tunnelling: Cambridge Advanced Learner's Dictionary
7. tunnelling: Wiktionary
8. tunnelling: Dictionary.com
9. tunnelling: Cambridge Essential American English Dictionary
10. Tunnelling: Online Plain Text English Dictionary
11. Tunnelling: AllWords.com Multi-Lingual Dictionary
12. tunnelling: FreeDictionary.org
13. tunnelling: TheFreeDictionary.com

Business (1 matching dictionary)

14. tunnelling: Legal dictionary

Computing (2 matching dictionaries)

15. tunnelling: Free On-line Dictionary of Computing
16. tunnelling: Encyclopedia

Medicine (2 matching dictionaries)

17. online medical dictionary (No longer online)
18. tunnelling: Medical dictionary

Miscellaneous (1 matching dictionary)

19. tunnelling: Idioms

Science (1 matching dictionary)

20. tunnelling: PHYSICAL ORGANIC CHEMISTRY

(Note: See tunnel as well.)

Definitions from Wiktionary (Tunnelling) ▸ noun:  Alternative form of tunneling [The act of burrowing a tunnel.] Similar: tunneller, burrowing, tunneler, trenching, excavation, underground, gravelling, concrete, excavate, rockburst, more... Opposite: bridging, spanning, connecting Types: quantum tunnelling, tunnelling effect, tunnelling current, more... Phrases: quantum tunnelling, tunnelling protocol, fn tunnelling, fowler-nordheim tunnelling, fowler nordheim tunnelling, more... Adjectives: mechanical, resonant, quantum, practical, assisted, direct, extensive, soft, superconductive, subaqueous, subcutaneous Colors:     charcoal,     slate gray,     midnight blue,     steel blue,     gunmetal, more... ▸ Words similar to tunnelling ▸ Usage examples for tunnelling ▸ Idioms related to tunnelling ▸ Wikipedia articles (New!) ▸ Popular adjectives describing tunnelling ▸ Words that often appear near tunnelling ▸ Rhymes of tunnelling ▸ Invented words related to tunnelling