hy·po·pla·sia (h??p?-pl??zh?)n. Incomplete or arrested development of an organ or a part.hy?po·plas?tic (-pl?s?t?k) adj.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.hypoplasia (?ha?p???plæz??) or hypoplastyn (Pathology) pathol incomplete development of an organ or part hypoplastic adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014hy?po?pla?sia (?ha? p??ple? ??, -?i ?) also hy?po?plas`ty (-?plæs ti) n. abnormal deficiency of cells or structural elements. [1895?1900] hy`po?plas?tic, adj. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.hypoplasiaa condition in which tissue or an organ of the body fails to grow to normal size. Cf. hypertrophy. ? hypoplastic, adj.See also: Sizea condition in which tissue or an organ of the body fails to grow to normal size. Cf. hypertrophy. ? hypoplastic, adj.See also: Body, Human-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.