Senses
姐夫 brother-in-law (older sister's husband)
term used by younger siblings to address their older sister's husband
姐夫 son-in-law
(archaic) a term used by parents-in-law to address their son-in-law
姐夫 client
(archaic) a term used by a brothel owner or prostitute to address a male client
姐夫 brother-in-law (husband's older brother)
dialectal term for a husband's older brother