-oidsuff.1. Resembling; having the appearance of; related to: acanthoid.2. One that resembles something specified or has a specified quality: humanoid.[Greek -oeid?s, from eidos, shape, form; see weid- 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.-oid suffix forming adjectives, suffix forming nounsindicating likeness, resemblance, or similarity: anthropoid. [from Greek -oeid?s resembling, form of, from eidos form]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014-oid a suffix meaning ?resembling,? ?like,? used in the formation of adjectives and nouns, and often implying an incomplete or imperfect resemblance to what is indicated by the preceding element: alkaloid; humanoid; planetoid. Compare -ode 1 . [