Sane

Part of speech: adjective

Pronunciation: /seɪn/

Definitions

1. Mentally healthy and able to think clearly and rationally
2. Possessing a healthy mind and the ability to reason logically and clearly
3. Having mental stability that enables one to think and behave in a reasonable and coherent manner

Etymology: Latin "sānus" meant "healthy" in the physical sense, and it was used of bodies, plants and climates long before it described minds. English "sane" is a learned borrowing from that Latin adjective, which means it came into the language through scholarly and literary channels rather than through everyday speech. The mental sense ("of sound mind") grew out of the idea of wholeness and good health, so a sane person was one whose mind was in working order, just as a sound body was one free of disease. The word has a twin that took a different route. "Sound," in the sense of healthy or whole, comes from a separate line of descent, so the two words are doublets: two English forms of one Latin ancestor, one arriving by ordinary inheritance and one by later borrowing. Their shared root is why "sane" and "sound" can feel like close relatives, even though their paths into English differ.

Synonyms: rational, sound, reasonable, lucid, sensible

Antonyms: insane, mad, irrational, unreasonable, crazy