Green’s Dictionary of Slang

1. to speak ill of someone, to gossip.

1882		Bristol Magpie 7 Dec. 13/2: We Hear [...] That the jangling gossip-mongers who frequent the mart of the five foolish virgins, should read Dr. Talmage's sermon in last week's Christian Herald. [...] That they are particularly fond of fault-finding in others, whilst their own is shamefully and systematically neglected.
1986		F. Taylor Auf Wiedersehen Pet Two 167: Audie Charles been jangling again, has she? There’s nothing in it, Neville.
1995		M. Simpson ‘Prufrock Scoused’ Catching Up with Hist. 21: Ders diss posh do wid lah-di-dah judies / janglin about ow thee once-t knew John Lenin.

2. to unnerve.

1951		R. Starnes Grant’s Tomb 15: ‘Last few times he got himself bounced by setting fire to the wastebaskets of managing editors [...] Managing editors can’t stand that sort of thing [...] It jangles them’.
1966		H.S. Thompson Hell’s Angels (1967) 121: One of the main kicks they get on a run comes from spooking and jangling citizens along the way.