-agogue or -agogsuff. A substance that stimulates the flow of: emmenagogue.[French, from Late Latin -ag?gus, from Greek -ag?gos, from ag?gos, drawing off, from agein, to lead, drive; see ag- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.-agogue or -agogn combining form1. indicating a person or thing that leads or incites to action: pedagogue; demagogue. 2. (Biochemistry) denoting a substance that stimulates the secretion of something: galactagogue. [via Late Latin from Greek ag?gos leading, from agein to lead] -agogic adj combining form -agogy n combining formCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014-agogue or -agog, a combining form with the meaning ?leader, bringer,? of that named by the initial element, occurring in loanwords from Greek (demagogue; pedagogue); used also in medical terms that denote substances inducing expulsion or secretion (hemagogue). [