The Collaborative International Dictionary of English v.0.48:
Clerical \Cler"ic*al\, a. [LL. clericalis. See Clerk.]
1. Of or pertaining to the clergy; suitable for the clergy.
"A clerical education." --Burke.
[1913 Webster]
2. Of or relating to a clerk or copyist, or to writing.
"Clerical work." --E. Everett.
[1913 Webster]
3. characteristic of the work performed by a clerk,
secretary, or copyist, or suitable to be performed by a
clerk. "Clerical staff."
[PJC]
A clerical error, an error made in copying or writing.
[1913 Webster]