n. Something to be added; especially text added as an appendix or supplement to a document.
n. A postscript.
n. The height by which the tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line.
the GNU version of the Collaborative International Dictionary of English
n. A thing to be added; an appendix or addition.
The Century Dictionary and Cyclopedia
n. A thing to be added; an addition; an appendix to a work.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. textual matter that is added onto a publication; usually at the end
Word Usage
"The COS Effect Readers, this addendum is in recognition that some of you (like me) may, whilst purchasing one of the above or similar TPD, wish to augment your wardrobe with simple, less expensive pieces."