(epidemiology) Isolation by avoiding physical contact with other individuals, especially in order to reduce the transmission of a contagious disease.

(Internet slang, of a video or image) Of exceptionally poor quality; low-resolution, grainy, or blurry.

(archaic) A quarrelsome person; one ready to pick quarrels.

(law, US) A doctrine protecting some government officials from suit if no prior court decision had declared similar conduct to be actionable, or if they acted in good faith.

In terms of or by means of quantum mechanics.

(quantum mechanics) A theory of quantum fields; the result of applying second quantization to Classical Relativistic Field Theory.

(quantum mechanics) A quantum operator-valued function of (any point in) space.

A positive quality that counteracts a negative quality.

a teaching qualification required in some schools in England and Wales.

(informal) An informal strategic forum between the United States, Japan, Australia, and India, focused on Asian security matters.