irony

Irony, n.

Etymology: [L. ironia, Gr. word: cf. F. ironie.]

1. Dissimulation; ignorance feigned for the purpose of confounding or provoking an antagonist.

2. A sort of humor, ridicule, or light sarcasm, which adopts a mode of speech the meaning of which is contrary to the literal sense of the words.

1 other Webster entry under this spelling

Irony, a.

1. Made or consisting of iron; partaking of iron; iron; as, irony chains; irony particles. [R.] Woodward.

2. Resembling iron taste, hardness, or other physical property.

Shades of meaning

Fernald has no entry of its own for irony; he lists it under banter.

Where he writes about it:

Irony, the saying one thing that the reverse may be understood, may be either mild or bitter. — from banter

none given