Synonyms for Talk through one's hat:

• v.

  •blab (verb)
  • betray,
  • gabble,
  • spill,
  • tell on,
  • blurt out,
  • shoot the breeze,
  • go on,
  • disclose,
  • squeal,
  • gab,
  • mouth,
  • let slip,
  • let out,
  • chatter,
  • run on,
  • tattle,
  • spill the beans,
  • peach,
  • jabber,
  • tell,
  • reveal,
  • yakkety-yak,
  • give away,
  • prattle,
  • yak,
  • run off at the mouth,
  • babble,
  • divulge,
  • blather.

• Other synonyms:

  •blab
  • Mouthing,
  • blathering,
  • yakkety yak,
  • peached,
  • Blathered,
  • blurting out,
  • Squealed,
  • Mouthed,
  • running on,
  • goes on,
  • run off at mouth,
  • Spilt,
  • letting out,
  • prattling,
  • Peaches,
  • Prattled.

Antonyms for Talk through one's hat:

• v.

  • blab
    conceal, hide, shut up, be quiet.