Useless, a.
Having, or being of, no use; unserviceable; producing no good end; answering no valuable purpose; not advancing the end proposed; unprofitable; ineffectual; as, a useless garment; useless pity. Not to sit idle with so great a gift Useless, and thence ridiculous. Milton.
Syn. -- Fruitless; ineffectual. -- Useless, Fruitless, Ineffectual. We speak of an attempt, effort, etc., as being useless when there are in it inherent difficulties which forbid the hope of success, as fruitless when it fails, not from any such difficulties, but from some unexpected hindrance arising to frustrate it; as, the design was rendered fruitless by the death of its projector. Ineffectual nearly resembles fruitless, but implies a failure of a less hopeless character; as, after several ineffectual efforts, I at last succeeded. Useless are all words Till you have writ "performance" with your swords. The other is for waiving. Beau. & Fl. Waiving all searches into antiquity, in relation to this controversy, as being either needless or fruitless. Waterland. Even our blessed Savior's preaching, who spake as never man spake, was ineffectual to many. Bp. Stillingfleet. -- Use"less*ly, adv. -- Use"less*ness, n.
Shades of meaning
Fernald has no entry of its own for useless; he lists it under vain.
Where he writes about it:
That which is useless, futile, or vain is inherently incapable of accomplishing a specified result. — from vain
Useless, in the widest sense, signifies not of use for any valuable purpose, and is thus closely similar to valueless and worthless. — from vain
That which is useless lacks actual fitness for a purpose; that which is vain lacks imaginable fitness. — from vain