Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


adjective con·scious \ˈkän(t)-shəs\

Simple Definition of conscious

  • : awake and able to understand what is happening around you

  • : aware of something (such as a fact or feeling) : knowing that something exists or is happening

  • : known or felt by yourself

Source: Merriam-Webster's Learner's Dictionary

Full Definition of conscious

  1. 1 :  perceiving, apprehending, or noticing with a degree of controlled thought or observation <conscious of having succeeded> <was conscious that someone was watching>

  2. 2 archaic :  sharing another's knowledge or awareness of an inward state or outward fact

  3. 3 :  personally felt <conscious guilt>

  4. 4 :  capable of or marked by thought, will, design, or perception

  5. 5 :  self-conscious

  6. 6 :  having mental faculties not dulled by sleep, faintness, or stupor :  awake <became conscious after the anesthesia wore off>

  7. 7 :  done or acting with critical awareness <a conscious effort to do better>

  8. 8 a :  likely to notice, consider, or appraise <a bargain-conscious shopper> b :  being concerned or interested <a budget-conscious businessman> c :  marked by strong feelings or notions <a race-conscious society>



Examples of conscious in a sentence

  1. The chances of being admitted conscious to a hospital without being pressed to produce a living will, have become virtually nil … —Joan Didion, New York Review of Books, 9 June 2005

  2. “Was she good-looking?” “Actually, my conscious mind no longer remembers anything about her physical appearance. She went the way of my seventh-grade French.” —Joseph Wambaugh, Finnegan's Week, 1994

  3. Incidentally, neither my mother nor I was conscious of any rudeness. —Flannery O'Connor, The Habit of Being, 1979

  4. Bilbo bowed. He had no hat to take off, and was painfully conscious of his many missing buttons. —J.R.R. Tolkien, The Hobbit, 1937

  5. Is the patient conscious yet?

  6. He was fully conscious when we found him.

  7. the capacity for conscious thought

Origin and Etymology of conscious

Latin conscius, from com- + scire to know

First Known Use: 1592

Synonym Discussion of conscious

aware, cognizant, conscious, sensible, alive, awake mean having knowledge of something. aware implies vigilance in observing or alertness in drawing inferences from what one experiences <aware of changes in climate>. cognizant implies having special or certain knowledge as from firsthand sources <not fully cognizant of the facts>. conscious implies that one is focusing one's attention on something or is even preoccupied by it <conscious that my heart was pounding>. sensible implies direct or intuitive perceiving especially of intangibles or of emotional states or qualities <sensible of a teacher's influence>. alive adds to sensible the implication of acute sensitivity to something <alive to the thrill of danger>. awake implies that one has become alive to something and is on the alert <a country always awake to the threat of invasion>.



noun con·scious \ˈkän(t)-shəs\

Definition of conscious

Examples of conscious in a sentence

  1. For myself, ever since 1922, when I saw my first picture, films have been barreling through my conscious to my unconscious, but insofar as they remain in my conscious, they get themselves arranged in hierarchies of value and, more important, affection. —Stanley Kauffmann, Before My Eyes, (1974) 1980

Origin and Etymology of conscious

(see 1conscious)

First Known Use: 1919

CONSCIOUS Defined for Kids


adjective con·scious \ˈkän-shəs\

Definition of conscious for Students

  1. 1 :  aware of facts, feelings, or some particular condition or situation <He … was painfully conscious of his many missing buttons. — J. R. R. Tolkien, The Hobbit>

  2. 2 :  known or felt by a person's inner self <conscious guilt>

  3. 3 :  mentally awake or active <He remained conscious following the accident.>

  4. 4 :  intentional <I made a conscious effort to be polite.>



Word Root of conscious

The Latin word scīre, meaning “to know” or “to understand,” gives us the root sci. Words from the Latin scīre have something to do with knowing or understanding. Science is the understanding of the world and how everything in it works. A person's conscience is the knowledge of right and wrong and the feeling that he or she should do right. Anything that is conscious knows what it is feeling.

Medical Dictionary



adjective con·scious \ˈkän-chəs\

Medical Definition of conscious

  1. 1:  capable of or marked by thought, will, design, or perception :  relating to, being, or being part of consciousness <the conscious mind> <conscious and unconscious processes>

  2. 2:  having mental faculties undulled by sleep, faintness, or stupor <became conscious after the anesthesia wore off>


\-lē\play adverb



noun con·scious

Medical Definition of conscious

Seen and Heard

What made you want to look up conscious? Please tell us where you read or heard it (including the quote, if possible).


looking or feeling very sad

Get Word of the Day daily email!


Take a 3-minute break and test your skills!


Which is a synonym of asperse?

beat divulge placate defame
Name That Thing

Test your visual vocabulary with our 10-question challenge!


Test Your Knowledge - and learn some interesting things along the way.