出典:Wiktionary
From Middle English, from Old French, from Latin -ibilis.
-ible
From Middle English, from Old French, from Latin -i- + -bulum (instrumental suffix) or -bula (instrumental suffix), from Proto-Indo-European *-dʰlom. Related to Latin suffixes -brum (candelabrum) and -bra (vertebra).
-ible
This use of -ible is not productive in English. Confusion may arise from mistaking nouns ending with this suffix as being forms derived from the adjectival suffixes mentioned in Etymology 1 above.
出典:Wikipedia