1. Having the necessary means, skill, know-how, or authority to do something; usually followed by to: "She is able to hold down a full time job and still have time for her children after school."
2. Physically, or mentally, equipped to do something; especially, because of circumstances and timing.
3. Having the power, skill, money, etc., that is needed to do something: "Matthew will buy a new pickup truck as soon as he is able to do it."
4. Having the freedom or opportunity to do something: "Jim, come and see us as soon as you are able to find the time."
5. Etymology: possibly from about 1375, borrowed from Old French hable, able; from Latin habilis, "easily managed, held", or "handled"; from habere, "to have, to hold".

The h of the Old French and Latin forms was never established in English, although Classical scholars tried to restore it in the 1500's and 1600's.

In the 1400's, habile was refashioned from Latin and is current today as a different form: able in modern use meaning "capable", habile, meaning "skillful". Derivative forms; such as, habilitate retain the h; ability has lost it.

1. Having enough power, skill, or means to do something; capable: "A cat is able to see in the dark."
2. Having more power or skill than usual; skillful: "She was an able teacher for more than 40 years."

"He turned out to be an able editor of the newspaper while his wife turned out to be one of the most able lawyers in her firm."

3. Expertly done; effective: "He presented an able speech even though he had just a few minutes to prepare for it."
4. Etymology: from Old French (h)able, from Latin habilis, "easily handled, apt", from habere, "to hold". "Easy to be held"; hence, "fit for a purpose".

The silent h- was dropped in English and resisted academic attempts to restore it in the 16th and 17th centuries, but some derivatives acquired the "h"; such as, with "habiliment" and "habilitate".