-ile Also -il and -ility
Forming adjectives and some nouns.
[Via French from Latin -ilis.]
Most words in -ile from this source are adjectives: agile, docile, ductile, fertile, fragile, juvenile, mobile, versatile, volatile. Several in statistics derive from Latin ordinal numerals, as in decile, each of ten equal groups into which a population can be divided; others are quartile, quintile, and percentile. A few nouns in -ile come from Latin words in -ilis: reptile (Latin reptilis, from repere, crawl), textile (Latin textilis, from texere, to weave). Others (like exile, facsimile, and imbecile) come from different Latin sources.
A few nouns in -il also derive from Latin -ilis (fossil, Latin fossilis, dug up; utensil, Latin utensilis, usable). However, most nouns in this ending derive from a variety of other sources, some from Old English (nostril), others from various French and Latin sources (fibril, lentil). The only common adjective in -il derived from a Latin word in -ilis is civil.
Abstract nouns are formed from adjectives in either -ile or -il by adding -ity: agility, civility, mobility, volatility.
See also -phile.