Helpless, a. — Webster enters it under “helpless”
1. Destitute of help or strength; unable to help or defend one's self; needing help; feeble; weak; as, a helpless infant. How shall I then your helpless fame defend Pope.
2. Beyond help; irremediable. Some helpless disagreement or dislike, either of mind or body. Milton.
3. Bringing no help; unaiding. [Obs.] Yet since the gods have been Helpless foreseers of my plagues. Chapman.
4. Unsupplied; destitute; -- with of. [R.] Helpless of all that human wants require. Dryden. -- Help"less*ly, adv. -- Help"less*ness, n.
Shades of meaning
Fernald lists helplessness only as an antonym, under power.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given