Fit or ready for use or service. Synonyms:functional, operational, usable, useable."The lawnmower is a bit rusty but still usable" , "An operational aircraft" , "The dishwasher is now in working order"
3.
Usable for a specific purpose. Synonym:practicable."A practicable solution"
... get used to it," he said in his short, gruff way. "You'd think it would become a matter of course, but it doesn't. That man's wife is dying of cancer. It's not an operable case. I told him that to-day. He asked for the truth and I gave it. I even gave my estimate of the time." He swung his chair around and looked out at the roof of the building below, and then turned sharply back to her. "You said a while ago that this looked like a home. Well, it's not. It's like ... — The Glory Of The Conquered • Susan Glaspell