The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
An affix consisting of a prefix and a suffix, such as the progressive present marker a- … -ing in dialectal English I'm a-going or the past participle marker y- … -t in archaic English yclept.transitive verb cir·cum·fixed, cir·cum·fix·ing, cir·cum·fix·es
To add as a circumfix.