brass neck/nerve

brass neck

1. noun Self-assured shamelessness, audacity, confidence, gall, or impudence. Primarily heard in UK. It takes a brass neck to make such an outlandish demand of me. The junior minister has shown a brass neck to the public regarding his plans to cut social welfare.
2. noun A person displaying or characterized by self-assured shamelessness, audacity, confidence, gall, or impudence. Primarily heard in UK. It's beyond me how a brass neck like him could be appointed as a manager.
3. verb To act with courageous self-confidence, especially in an audacious, impudent, or shameless manner. Primarily heard in UK. We didn't have enough money for the train ride, but we thought we'd just brass neck it if anyone gave us grief.
See also: brass, neck
Farlex Dictionary of Idioms.

brass neck

cheek or effrontery. informal
See also: brass, neck
Farlex Partner Idioms Dictionary

ˌbrass ˈneck/ˈnerve

(British English, informal) a combination of confidence and lack of respect: I didn’t think she would have the brass neck to do that.
See also: brass, neck, nerve
Farlex Partner Idioms Dictionary
See also:
  • brass neck
  • some neck
  • walk heavy
  • swag
  • have a way with words
  • have the gift of (the) gab
  • have the gift of gab
  • waltz up
  • waltz up (to someone or something)
  • have a gift for gab