chew the fat
informal

- to talk with someone in an informal and friendly way

The Cambridge English Dictionary

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PHRASE ORIGIN

The etymology of "chew the fat" is quite interesting and somewhat controversial, with multiple theories but uncertain origins.

It first appears as a British military expression for grumbling or complaining during the late 19th century and appears in the famous 1891 British compilation Slang and Its Analogues by John Farmer and William Henley. It became more common over the next decade on both sides of the Atlantic and weakened until it just meant idle chat.

Theories about origin:

1. Sailor theory: Although some sources attribute the phrase "chew the fat" to sailors, who during a period of resting and conversing, or while working together, would chew on salt-hardened fat, there are no reliable historical recordings of this practice.

2. Post-meal socializing: One of the possible origins is from the fact that after a meal people would go into their sitting room with their guests and chit chat while chewing on the fat left over from a meal.

3. Simple jaw movement analogy: Probably just from comparison of the jaw movements in chewing to the jaw movements in talking.

The older phrase "chew the rag," is considered to be synonymous;... with some speculating that fat refers to juicy items of gossip and rag to ladies' sewing circles and the cloth they worked on while chatting.

Today both expressions are largely synonyms for a friendly talk or gossip session.

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SYNONYMS

chat, CHEW THE FAT, chew the rag, chinwag, converse, discuss things, have a talk (a conversation, a tête-à-tête), natter, to jaw, rabbit, rap, shoot the breeze, talk about this and that, yak, yap