Ridiculous, a.
Etymology: [L. ridiculosus, ridiculus, fr. ridere to laigh. Cf. Risible.]
1. Fitted to excite ridicule; absurd and laughable; unworthy of serious consideration; as, a ridiculous dress or behavior. Agricola, discerning that those little targets and unwieldy glaives ill pointed would soon become ridiculous against the thrust and close, commanded three Batavian cohorts . . . to draw up and come to handy strokes. Milton.
2. Involving or expressing ridicule. [r.] [It] provokes me to ridiculous smiling. Shak.
Syn. -- Ludicrous; laughable; risible; droll; comical; absurd; preposterous. See Ludicrous. --- Ri*dic"u*lous*ly, adv. -- Ri*dic"u*lous*ness, n.
Shades of meaning
Fernald has no entry of its own for ridiculous; he lists it under absurd, queer.
Where he writes about it:
The ridiculous or the nonsensical is worthy only to be laughed at. — from absurd
The lunatic's claim to be a king is ridiculous; the Mother Goose rimes are nonsensical. — from absurd
Queer is transverse or oblique, aside from the common in a way that is comical or perhaps slightly ridiculous. — from queer
That which is grotesque in the material sense is irregular or misshapen in form or outline or ill-proportioned so as to be somewhat ridiculous; the French bizarre is practically equivalent to grotesque. — from queer