We found 8 dictionaries that define the word registration numbers:

General (4 matching dictionaries)

1. registration numbers: Collins English Dictionary
2. registration numbers: Vocabulary.com
3. registration numbers: Cambridge Advanced Learner's Dictionary
4. registration numbers: TheFreeDictionary.com

Business (2 matching dictionaries)

5. registration numbers: Legal dictionary
6. registration numbers: Financial dictionary

Computing (1 matching dictionary)

7. registration numbers: Encyclopedia

Medicine (1 matching dictionary)

8. registration numbers: Medical dictionary

(Note: See registration_number as well.)

Definitions from Wiktionary (registration number) ▸ noun:  (UK) Series of letters and numbers on shown on the front and back of a motor vehicle. ▸ Also see registration_number ▸ Words similar to registration numbers ▸ Usage examples for registration numbers ▸ Idioms related to registration numbers ▸ Wikipedia articles (New!) ▸ Words that often appear near registration numbers ▸ Rhymes of registration numbers ▸ Invented words related to registration numbers