"Chin-wagging" is a colloquial term used to describe idle chatter or gossip. There are several similar expressions that convey similar meanings and connotations. "Jawing" or "yapping" are used to describe excessive talking or chatting, while "prattling" or "babbling" tend to have a slightly negative connotation and suggest nonsensical or trivial conversation. "Gassing" is also used to describe aimless chatter, often between two people. "Chattering" is a more formal alternative to "chin-wagging" and refers to incessant or trivial talking. In summary, there is a diverse range of synonyms for "chin-wagging," each with subtly different meanings and nuances.