be (one's) pigeon

be (one's) pigeon

To be one's area of expertise or responsibility. I can't approve expense reports, but Betty can—that's her pigeon.
See also: pigeon
Farlex Dictionary of Idioms.

be someone's pigeon

BRITISH, OLD-FASHIONED
If something is your pigeon, you have to deal with it. I'm glad this is your pigeon rather than mine. Note: Originally this expression was `that's not my pidgin'. The word `pidgin' represents a 17th century Chinese pronunciation of the word `business'. The expression literally meant the same as `that's not my business'.
See also: pigeon
Collins COBUILD Idioms Dictionary, 3rd ed.

be someone's pigeon

be someone's concern or affair.
In this phrase, the word pigeon derives from pidgin , as in pidgin English , the term for a grammatically simplified form of a language used for communication between people not sharing a common language. Pidgin itself represents a Chinese alteration of the English word ‘business’: it entered the English language with the meaning ‘occupation’ or ‘affair(s)’ in the early 19th century, emerging from the hybrid of English and other languages used at that time between Europeans and the Chinese for trading purposes.
See also: pigeon
Farlex Partner Idioms Dictionary

be somebody’s pigeon

(old-fashioned, British English) be somebody’s responsibility or business: Somebody needs to write a report on training for the manager, but it’s not my pigeon. Gustav will have to tell them first, it’s his pigeon.
See also: pigeon
Farlex Partner Idioms Dictionary
See also:
  • be somebody's pigeon
  • be someone's pigeon
  • pigeon
  • pigeon-eyed
  • milk the pigeon
  • skrag
  • living impaired
  • put someone to bed with a shovel