be someone'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.
be someone's pigeonBRITISH, 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'.
be someone's pigeonbe 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.