instinct

What it means

1. countableuncountableA natural or inherent impulse or behaviour.

   Many animals fear fire by instinct.

   2 more examples

   By a divine instinct, men's minds mistrust / Ensuing dangers.

   c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act II, scene iii]

   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. countableuncountableAn intuitive reaction not based on rational conscious thought.

   Debbie's instinct was to distrust John.

   1 more example

   an instinct for order; to be modest by instinct

In a sentence

Many animals fear fire by instinct.

Where it comes from

1. Latinīnstīnctus
2. Englishinstinct

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