from The American Heritage® Dictionary of the English Language, 4th Edition
- suffix Of, relating to, or capable of: audile.
- suffix A division of a specified size in the range of a statistic: percentile.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- suffix tending to, or capable of
Middle English, from Old French, from Latin -ilis, -īlis.
Probably from -ile1.(American Heritage® Dictionary of the English Language, Fourth Edition)
Latin -ilis (Wiktionary)