Green’s Dictionary of Slang

gab n.2

[Scot. gab, talk volubly]

1. [19C+] (also gabs) idle chatter.

2. [19C+] talk, conversation, esp. charming and persuasive.

3. [late 19C] a (foreign) language.

4. [1920s] (US) one who talks too freely, one who cannot keep a secret.

5. [1990s+] as the gabs, a propensity to talk too much.

In phrases

all gab and guts (like a young crow) (adj.)

[] irrepressibly and noisly loquacious.

stow one’s gab (v.) (also cheese one’s gabs, cut one’s gab, hold..., stash...)

[early 19C+] to stop talking, esp. as imper.