sane

sane — adjective

1. in a normal mental state, without any illness that affects how you think, feel,

1.adjectiveB1
Definition

in a normal mental state, without any illness that affects how you think, feel, or behave

Example

Élise was declared sane and left the hospital after months of therapy.

legal/medical register: be declared sane

The court had to decide whether the defendant was sane during the crime.

pattern: whether + [subject] + was sane

Common collocations
  • remain sane
  • keep someone sane
  • perfectly sane
  • completely sane
  • declare someone sane
Synonyms
  • of sound mind

    formal, legal register; used in wills and court proceedings

  • mentally sound

    clinical register, often used in medical reports

  • rational

    broader; can describe thinking ability rather than mental health

Antonyms
  • insane

    direct opposite; can be offensive in casual use

  • mentally ill

    clinical term; more precise and less judgmental

Grammar Patterns

be + sane

no sane + noun

Usage Note

Frequently used in legal and medical contexts, especially in expressions such as 'to be declared sane' or 'to remain sane'. In everyday conversation, 'sane' in this sense is less common than 'in one's right mind' or simply 'healthy'.

Common Mistakes

She is very sane today.
She is sane.' or 'The doctors confirmed she was sane.
Sanity is a stable mental state, not a quality that varies day by day.

2. showing practical, reasonable, and well-balanced thinking — for example, choosin

2.adjectiveB1
Definition

showing practical, reasonable, and well-balanced thinking — for example, choosing a safe plan over a risky one

Example

Andrés made the sane choice to save money instead of spending it on a party.

collocation: sane choice

Moving to a quieter neighbourhood was a sane decision for Nadia and her children.

collocation: sane decision

Common collocations
  • sane choice
  • sane decision
  • sane advice
  • sane approach
  • the sane thing to do
Synonyms
  • sensible

    more common in everyday speech; slightly less formal

  • reasonable

    emphasises fairness and logic rather than safety

  • rational

    focuses on logical thinking over emotion

  • level-headed

    informal; describes a person's calm and balanced nature

Antonyms
  • foolish

    opposite of using good judgment; implies a lack of foresight

  • unreasonable

    opposite of reasonable; suggests unfairness or illogic

Grammar Patterns

a sane + noun

the sane thing to do

sane + noun

Usage Note

Often appears in fixed phrases like 'the sane thing to do' or 'a sane choice', describing practical decisions rather than brilliant or perfect ones. This sense does not refer to mental health.

Common Mistakes

That is a very sane opinion.
That is a sane approach to the problem.
'sane' implies practical, reasonable judgment, not just personal preference.

Word family

Synonym discussion

Sense: adjective/2

Sane, sensible, reasonable, rational, and level-headed all describe good judgment, but each has a different focus. Sane (sense 2) emphasises that a decision is practical and avoids unnecessary risk — it carries a slight contrast with 'crazy' or 'wild' ideas. Sensible is the closest everyday synonym, but it is softer and more neutral; a sensible person might simply choose a comfortable option, while a sane decision often implies rejecting a dangerous or absurd alternative. Reasonable focuses on fairness and logic that others can agree with, whereas rational stresses thinking based on facts rather than emotions. Level-headed is informal and describes a person's calm temperament under pressure. For example: 'It was sane to bring extra water on the hike' (avoids risk), 'It was sensible to wear comfortable shoes' (practical), 'It was reasonable to expect a refund' (fair), 'It was rational to check the weather forecast first' (logical), and 'She stayed level-headed when the car broke down' (calm).

sensible ↗reasonable ↗rational ↗level-headed

Common collocations

Adverbs

Etymology

LatinFrenchEnglish

The word 'sane' comes from Latin 'sanus', meaning 'healthy' or 'sound'. It entered English in the early 1600s through French 'sain', and was originally used for physical health before narrowing to mental health. The sense of 'showing good judgment' developed naturally from the idea of a 'sound mind', appearing in English by the 1800s.