- (computing, X Window System) An integer that uniquely identifies a text string.
- (physics) In the Standard Model, an elementary subatomic particle which forms matter. Quarks have never been found alone as of this writing, They combine to form hadrons, such as protons and neutrons.
- (Falkland Islands (informal)) The black-crowned night heron, Nycticorax nycticorax.
- A soft creamy cheese, eaten throughout northern, central, and eastern Europe, very similar to cottage cheese except that it is usually not made with rennet.