n. pl. a·cic·u·lae (-lē′)
A slender, needlelike part or structure, such as a spine or bristle of certain plants and animals or a crystal of certain minerals.
[Latin, hairpin, diminutive of acus, needle; see ak- in the Appendix of Indo-European roots.]
a·cicu·late (-lĭt, -lāt′), a·cicu·lat′ed (-lā′tĭd) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.