Below is a link to the St. Louis County Public Library's web page relating to Freedmen's Bureau terms and terminology of the records. Ruth Ann Hager is a great reference specialist at the library. She's lectured extensively on African American subjects and has done extensive research in the records housed at the library.

Here's another link to another page within the library's web site that might be useful to you.

Julius K. Hunter & Friends African American Research Collection
http://www.slcl.lib.mo.us/branches/hq/sc/jkh/sc_jkh_main.htm