-ible

Alternative forms

• -able productive

From Middle English, from Old French, from Latin -ibilis

Full definition of -ible

Suffix

1. An adjective suffix, now usually in a passive sense; forms adjectives meaning:
1. able to be
2. relevant or suitable to, in accordance with
3. expressing capacity or worthiness in a passive senseconvertible

Usage notes

The form -able is used in the same sense and is pronounced the same.

Generally not productive in English – most words ending in -ible are borrowed from Latin, or Old or Middle French, while -able is more common for producing new words. Examples of production in English include collectible.

In general, forms derived from Latin verbs of the second, third, and fourth conjugations take -ible, as well as a few words whose roots end in a soft c or g. All other words take -able, particularly words from the Latin first conjugation, words that evolved through French, and words from Anglo-Saxon.

Fowler, in his English Usage, recommended using -ible for simplicity in spelling with any verb whose root ends in a soft c or g (such as changible vs. changeable), but this recommendation has generally not been followed.

Adjectives ending in -ible are occasionally nominalized, as in dirigible, foible, submersible. The adjective sense may become obsolete, as in foible.

A few words end in “ible” but are not related to this suffix, instead being of different origin, generally a similar Latin suffix. Examples include crucible and mandible.

Derived terms

• -ibly

• From Middle English, from Old French, from Latin -i- + -bulum ("instrumental suffix") or -bula ("instrumental suffix"), from Proto-Indo-European *-dÊ°lom ("instrumental suffix"). Related to Latin suffixes -brum (candelabrum) and -bra (vertebra).

Suffix

1. An instrumental suffix; forms nouns representing:
1. a tool or instrument.cruciblemandiblethurible
2. a place or locationvestible

Usage notes

This use of -ible its related form -able are not productive in English. Confusion may arise from mistaking nouns ending with these suffixes as being forms derived from the adjectival suffixes mentioned in Etymology 1 above.

Derived terms