Definitions for -able
Random House Webster's College Dictionary
a•bleˈeɪ bəl(adj.)a•bler, a•blest.
having the necessary power, skill, resources, or qualifications to do something:
able to read music; not able to vote.
having or showing unusual talent, intelligence, skill, or knowledge:
an able leader.
Origin of able:
1275–1325; ME < MF < L habilis easy to handle, adaptable =hab(ēre) to have, hold +-ilis -ile1
a suffix meaning “capable of, susceptible of, fit for, tending to, given to,” associated in meaning with the word able , occurring in loanwords from Latin (laudable); used in English to form adjectives from stems of any origin (teachable; photographable).
Ref: Compare -ble, 1 -ible.
Origin of -able:
ME < OF < L -ābilis
An adjective suffix, now usually in a passive sense; forms adjectives meaning possible, or fit.
an adjective suffix now usually in a passive sense; able to be; fit to be; expressing capacity or worthiness in a passive sense; as, movable, able to be moved; amendable, able to be amended; blamable, fit to be blamed; salable