DuckCorp Dico

Found one definition

1.                 From English - Polish Piotrowski+Saloni/FreeDict dictionary ver. 0.2:
                   
   
   
                   
                     
   hat /hæt/ <N>
    1.  kapelusz
    2.  keep sth under one's hat (keep V: NP :under PROPOSS :hat)
    - trzymać coś dla siebie
    3.  it is an old hat (:it :is :an :old :hat)
    - to już stara historia
    4.  talk through one's hat (talk V: :through PROPOSS :hat)
    - opowiadać bzdury