Green’s Dictionary of Slang

1. (US) a county attorney.

1953

J. Thompson Savage Night (1991) 136: The county attorney was going up the stairs, and the deputy took us into the c.a.’s office.

2. (US, also c/a, ca) corporal arts, i.e. corporal punishment.

1987

personal ad. in restroom Murray & Murrell Lang. Sadomasochism (1989) 47: Discipline lovers, take note: I’m the mistress of all CA, BD, SM, and I command you to call me now [Ibid.] See me now for the best C.A. in town — well versed in French, Greek, Roman, Irish, willing to try anything twice.