a. Characterized by or having an awareness of one's environment and one's own existence, sensations, and thoughts. See Synonyms at aware.
b. Mentally perceptive or alert; awake: The patient remained fully conscious after the local anesthetic was administered.
2. Capable of thought, will, or perception: the development of conscious life on the planet.
3. Subjectively known or felt: conscious remorse.
4. Intentionally conceived or done; deliberate: a conscious insult; made a conscious effort to speak more clearly.
5. Inwardly attentive or sensitive to something: As he spoke, he became increasingly conscious of his high-pitched voice.
6. Showing awareness of or preoccupation with something. Often used in combination: a cost-conscious approach to health care; a value-conscious shopper.
In psychoanalysis, the component of waking awareness perceptible by a person at any given instant; consciousness.
[From Latin cōnscius : com-, com- + scīre, to know; see skei- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.