We found one dictionary that defines the word doesn't know what he's talking about:

General (1 matching dictionary)

1. doesn't know what he's talking about: Merriam-Webster

▸ Words similar to doesn't know what he's talking about ▸ Usage examples for doesn't know what he's talking about ▸ Idioms related to doesn't know what he's talking about ▸ Wikipedia articles (New!) ▸ Words that often appear near doesn't know what he's talking about ▸ Rhymes of doesn't know what he's talking about ▸ Invented words related to doesn't know what he's talking about