mul·ti·cel·lu·lar (m?l?t?-s?l?y?-l?r, -t?-)adj. Having or consisting of many cells: multicellular organisms.mul?ti·cel?lu·lar?i·ty (-l?r??-t?) n.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.multicellular (?m?lt??s?lj?l?) , multicell or multicelledadj (Biology) having many cellsCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014mul·ti·cel·lu·lar (m?l?t?-s?l?y?-l?r) Having or consisting of many cells: multicellular organisms. Compare unicellular.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.multicellularComposed of many cells.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited