The term 'Black dog' is related to -

• Black dog:
English meaning: a way of referring to feelings of depression (= great sadness and lack of energy).
Bangla meaning: বিষন্নতার অনুভূতি উল্লেখ করার একটি উপায়।

Example: 
- There were times when he wrestled with the black dog and couldn't write.
- She tried to keep busy to avoid the black dog that had haunted her since her teenage years.
- He often described his struggles with the black dog as a constant battle with his own thoughts.

Source: Cambridge Dictionary.