Definition of "trimorphic" [tri•mor•phic]

• Biology Having or occurring in three differing forms. (adjective)
• Chemistry Crystallizing in three distinct forms. (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.

• "Not until men entered that closed system could humans escape biology by becoming the psychologically trimorphic family: mother-father-baby."
• "The flowers are trimorphic with long, short or mid-length styles."
• "If Natural Selection could not accumulate varying degrees of sterility for the plant's benefit, then how did sterility ever come to be associated with _one cross_ of a trimorphic plant rather than another?"