Definition of "monomorphic" []

• Chemistry Having only one form, as one crystal form. (adjective)
• Zoology Having one or the same genotype, form, or structure through a series of developmental changes. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Male and female penguins are very similar in appearance and can be impossible to distinguish without behavioral cues (referred to as monomorphic)."
• "Auks are sexually monomorphic, meaning that males and females look the same."
• "These birds are monomorphic, which means that males and females look the same to human eyes, anyway."