Meaning : Capable of being treated by surgical operation.
Example :
An operable cancer.
Meaning : Fit or ready for use or service.
Example :
The toaster was still functional even after being dropped.
The lawnmower is a bit rusty but still usable.
An operational aircraft.
The dishwasher is now in working order.
Synonyms : functional, operational, usable, useable
Meaning : Usable for a specific purpose.
Example :
An operable plan.
A practicable solution.
Synonyms : practicable