instinct

Etymology

From Latin īnstinctus, past participle of īnstinguō (“to incite, to instigate”), from in (“in, on”) + stinguō (“to prick”).

noun

1. A natural or inherent impulse or behaviour.
   Many animals fear fire by instinct.
   In spite of these qualifications, the broad distinction between instinct and habit is undeniable. To take extreme cases, every animal at birth can take food by instinct, before it has had opportunity to learn; on the other hand, no one can ride a bicycle by instinct, though, after learning, the necessary movements become just as automatic as if they were instinctive. 1921, Bertrand Russell, The Analysis of Mind
2. An intuitive reaction not based on rational conscious thought.
   an instinct for order; to be modest by instinct
   Debbie's instinct was to distrust John.

adj

1. (archaic) Imbued, charged (with something).
   a noble performance, instinct with sound principle 1838, Henry Brougham, Historical Sketches of Statesmen Who Flourished in the Time of George III
   Her eyes, whose colour I had not at first known, so dim were they with repressed tears, so shadowed with ceaseless dejection, now, lit by a ray of the sunshine that cheered her heart, revealed irids of bright hazel – irids large and full, screened with long lashes; and pupils instinct with fire. 1857, Charlotte Brontë, The Professor
   It was a most Bedlamite catalogue of horrors, which, if true, made the wholesome moors a place instinct with tragedy. 1899, John Buchan, No Man's Land