Chaff

chaff [CHAF]
v. to tease in a good-natured manner; to engage in banter
n. banter

[Origin unknown, but probably from chafe ("to irritate; to annoy")]

From the saying, "separate the wheat from the chaff," which means "to separate what is useful or valuable from what is worthless," chaff is fairly well known. In that sense, chaff is "the husks of grains and grasses separated from the seed by threshing and winnowing." However, chaff has another meaning, "banter," which is unrelated.

Banter is "an exchange of light, playful, teasing remarks; good-natured raillery." Besides chaff, we have quite a few nice synonyms in English for playful kidding, teasing and joking among friends. Here are some: badinage ("light, playful banter"); jest ("a bantering remark"); josh ("to chaff; banter in a teasing way"); persiflage ("light, bantering talk or writing"); rag on ("to subject to a teasing, esp. in an intense or prolonged way"); raillery ("good-humored ridicule"); razz ("to deride; make fun of; tease"); and ridicule ("to deride; make fun of").

In Love, Poverty and War, Christopher Hitchens quotes Evelyn Waugh from Waugh's work as a foreign correspondent for the Express newspaper, where Mr. Waugh described the playful banter at a bar in Sarajevo:

All over the lounge and dining-room they sat and stood and leaned; some whispered to each other in what they took to be secrecy; others exchanged chaff and gin.

In his novel Put Out More Flags, Evelyn Waugh again employs chaff:

There was still a great deal of the schoolboy about Alastair; he enjoyed winter sports and sailing and squash racquets and the chaff round the bar at Bratt's.