{v. phr.}, {informal} To say something without knowing or understanding the facts; talk foolishly or ignorantly. * /John said that the earth is nearer the sun in summer, but the teacher said he was talking through his hat./
TALK THROUGH ONE'S HAT
Meaning of TALK THROUGH ONE'S HAT in English
Dictionary of English idioms . Словарь английских идиом. 2012