anesthesia

IPA/ˌæn.əsˈθiː.zi.ə/
KK[ˌænɪsθˈiʒə]IPA/ˌæn.əsˈθiː.zi.ə/

anesthesia — noun

1. the way people in the United States write the word that British English spells a

1.nounB2
Definition

the way people in the United States write the word that British English spells as 'anaesthesia'

Example

My laptop's spell-check flagged 'anaesthesia', so I changed it to 'anesthesia'.

American vs British spelling distinction

The author replaced every 'anaesthesia' with 'anesthesia' before submitting to the US journal.

Usage Note

Only covers the US versus British spelling difference. For the medical meanings, see senses 2 and 3 below.

Common Mistakes

The British doctor wrote anesthesia in the report.
The British doctor wrote anaesthesia in the report.
British English uses the 'ae' diphthong; American English drops it to a single 'e'.

2. a medical condition in which a person cannot feel pain or other physical sensati

2.nounB2
Definition

a medical condition in which a person cannot feel pain or other physical sensations in all or part of the body, either because a doctor or nurse has given them a drug for a procedure such as an operation, or because of a disease or injury

Example

The patient was under general anesthesia while the surgical team repaired her damaged knee.

collocation: under anesthesia

Local anesthesia numbed only Wei's left foot, so he could still move his right toes.

contrast: local vs general anesthesia

Common collocations
  • general anesthesia
  • local anesthesia
  • regional anesthesia
  • under anesthesia
  • undergo anesthesia
  • recover from anesthesia
  • administer anesthesia
  • anesthesia wears off
Synonyms
  • numbness

    everyday, non-technical term for loss of sensation; can be caused by cold, pressure, or minor injury, not just medical procedures

  • analgesia

    specifically inability to feel pain while other sensations (touch, pressure) may remain; a more precise medical term

Antonyms
  • sensation

    the ability to feel physical stimuli such as touch, pain, or temperature

  • feeling

    everyday opposite of anesthesia; normal sensory awareness

Usage Note

Typically uncountable. The most common collocations are 'under anesthesia' (during the period of induced numbness) and 'general/local/regional anesthesia' to specify the type. Frequently appears with the verbs 'administer', 'undergo', and 'recover from'.

Common Mistakes

I stayed awake during my surgery because of general anesthesia.
I stayed awake during my surgery because of local anesthesia.
General anesthesia makes you completely unconscious; local anesthesia numbs only one area while you remain awake.

3. a substance, given by a doctor or a nurse, that stops a person from feeling pain

3.nounC1
Definition

a substance, given by a doctor or a nurse, that stops a person from feeling pain during a medical procedure such as a surgery or a visit to the dentist

Example

The nurse prepared a bottle of liquid anesthesia and connected it to the drip.

anesthesia as a physical substance (prepared, administered)

Dr. Okonkwo waited until the anesthesia took full effect before making the first cut.

verb pattern: anesthesia + take effect

Common collocations
  • liquid anesthesia
  • inject anesthesia
  • anesthesia takes effect
  • anesthesia wears off
  • a dose of anesthesia
Synonyms
  • anesthetic

    the more standard term for the drug itself; 'anesthesia' in sense 3 is an informal or non-technical extension

  • painkiller

    general term for any drug that relieves pain; broader than anesthesia, which causes temporary loss of all sensation, not just pain

  • numbing agent

    descriptive everyday term; less technical than 'anesthetic'

Usage Note

When used as a countable noun ('several different anesthesias were tested'), it refers to specific types or formulations of anesthetic agents. The more common word for the substance itself is 'anesthetic', but 'anesthesia' is also used in this sense, especially in spoken medical contexts.

Common Mistakes

The patient asked for more anesthesia because the first injection did not work.
The patient asked for more anesthetic because the first injection had not fully numbed the area.
While native speakers do use 'anesthesia' for the drug informally, the precise technical term for the agent is 'anesthetic'.

Word family

Synonym discussion

Sense: noun/2

Anesthesia is the formal medical term for total or partial loss of physical sensation, including but not limited to pain. It can be deliberately induced for surgery (general or local) or result from injury or disease. Numbness is the everyday word for a lack of feeling — it can come from cold weather, sitting in one position too long, or a minor injury, and it does not require medical intervention. Analgesia is a more precise medical term that refers specifically to the inability to feel pain while other sensations (touch, pressure, temperature) remain intact; an epidural during childbirth provides analgesia, not full anesthesia. Insensitivity is broader still: it can mean a physical inability to feel (the insensitivity of scar tissue) or a figurative emotional coldness. In short: anesthesia is the clinical state managed by medical professionals; numbness is the casual term; analgesia is pain-specific; and insensitivity extends beyond the physical.

anesthesia ↗numbness ↗analgesiainsensitivity ↗

Common collocations

Nouns

  • anesthesiologist
  • anesthesia machine
  • anesthesia department
  • anesthesia team
  • anesthesia mask

Adverbs

Phrases

  • general anesthesia
  • local anesthesia
  • regional anesthesia
  • spinal anesthesia
  • under anesthesia
  • recover from anesthesia

Prepositions

Etymology

GreekEnglish

The word 'anesthesia' comes from the Greek 'anaisthēsia', meaning 'lack of sensation'. This was formed from 'an-' (without) + 'aisthēsis' (sensation, feeling). The English physician and poet Oliver Wendell Holmes Sr. proposed the term in 1846 to describe the state produced by the newly discovered anesthetic gas ether, replacing older terms like 'suspended animation' and 'state of insensibility'. The word entered general medical use within months and has since spread into everyday language.

First known use

1708

1708, in the meaning defined at sense 1