The idiom "To talk someone's head off" means -

• To talk someone's head off (idiom)
English Meaning: to talk to someone for a long time, usually loudly, to bore or weary someone by excessive talk; talk incessantly
Bangla meaning: সাধারণত দীর্ঘক্ষন ধরে কথা বলা, বা উচ্চস্বরে কথা বলা, অতিরিক্ত কথা বলা।

• সুতরাং, অপশন অনুযায়ী, The idiom "To talk someone's head off" means - To talk excessively.

Example Sentence: She talked my head off.

Source: Collins Dictionary and Cambridge Dictionary.