'Big Bertha' definitions:

Definition of 'Big Bertha'

From: GCIDE

Bertha \Ber"tha\, n. [F. berthe, fr. Berthe, a woman's name.] A kind of collar or cape worn by ladies. [1913 Webster]
Big Bertha, n. a large cannon used by the German army during World War I. [PJC] [1913 Webster]