1. Not awake; asleep: "[He] lay dormant on the scruffy couch, his mouth open, reading glasses slumped on his swollen nostrils" (Steven Heighton).
2. Present but not active or manifest though capable of becoming so: "a harrowing experience which ... lay dormant but still menacing" (Charles Jackson). See Synonyms at inactive.
3. Temporarily inactive: a dormant volcano.
4. Being in a condition of biological rest or inactivity characterized by cessation of growth or development and the suspension of many metabolic processes: a dormant bud; a dormant bacterium.
[Middle English, from Old French, from present participle of dormir, to sleep, from Latin dormīre.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.