Joke, n.
Etymology: [L. jocus. Cf Jeopardy, Jocular, Juggler.]
1. Something said for the sake of exciting a laugh; something witty or sportive (commonly indicating more of hilarity or humor than jest); a jest; a witticism; as, to crack good-natured jokes. And gentle dullness ever loves a joke. Pope. Or witty joke our airy senses moves To pleasant laughter. Gay.
2. Something not said seriously, or not actually meant; something done in sport. Inclose whole downs in walls, 't is all a joke. Pope. In joke, in jest; sportively; not meant seriously. -- Practical joke. See under Practical.
2 other Webster entries under this spelling
Joke, v. t. [imp. & p. p. Joked; p. pr. & vb. n. Joking.]
To make merry with; to make jokes upon; to rally; to banter; as, to joke a comrade.
Joke, v. i.
To do something for sport, or as a joke; to be merry in words or actions; to jest. He laughed, shouted, joked, and swore. Macaulay.
Syn. -- To jest; sport; rally; banter. See Jest.
Shades of meaning
Fernald has no entry of its own for joke; he lists it under wit.
He lists it without comment; the entries above explain its neighbors.