so·mat·ro·pin (s?-m?t?r?-p?n, s??-m?-tr??-)n. See human growth hormone.[Greek s?ma, body; see teu?- in Indo-European roots + -tropin.]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.