We found 10 dictionaries that define the word fifteens:

General (7 matching dictionaries)

1. fifteens: Merriam-Webster
2. fifteens: Collins English Dictionary
3. fifteens: Vocabulary.com
4. fifteens: Wordnik
5. fifteens: Wiktionary
6. Fifteens: Wikipedia, the Free Encyclopedia
7. fifteens: TheFreeDictionary.com

Computing (1 matching dictionary)

8. fifteens: Encyclopedia

Slang (1 matching dictionary)

9. Fifteens: Urban Dictionary

Sports (1 matching dictionary)

10. Hickok Sports Glossaries (No longer online)

(Note: See fifteen as well.)

Definitions from Wiktionary (fifteens) ▸ noun:  (historical) A medieval tax on movable property. Similar: cardinal, XV, fifteener, fives, fifteensome, trething, quinzieme, tithe, fifteenness, decime, more... Opposite: zero, nil, nothing ▸ Words similar to fifteens ▸ Usage examples for fifteens ▸ Idioms related to fifteens ▸ Wikipedia articles (New!) ▸ Popular adjectives describing fifteens ▸ Words that often appear near fifteens ▸ Rhymes of fifteens ▸ Invented words related to fifteens