(physics) The only stable isotope of sodium, ²³₁₁Na, having eleven protons and twelve neutrons

(idiomatic, archaic, chiefly US) To leave, particularly quickly or at an advantageous time. / (idiomatic, archaic, chiefly US) To be forced to leave quickly.

(idiomatic, dated, rare, chiefly US) A fictitious place or a generic place that could refer to any location.

Abbreviation of uranium-235.

(physics) A fissile isotope of uranium, used for energy generation and in atomic weapons, containing one hundred and forty-three neutrons. It has a half-life of 7·038×10⁸ years; it decays into thorium-231 and ultimately lead.

(telecommunications, computing) Recommended Standard 232; the standard for serial binary signals between a DTE and a DCE.

Abbreviation of twenty-third.