The decade of the 2020s. / The decade of the 1920s. / Temperatures from 20 to 29 degrees. / Ages between 20 and 29.

(Internet) The second generation of the World Wide Web, especially the movement away from static webpages to dynamic and shareable content, social networking, and online collaboration.

(physics) A radioactive isotope of polonium, ²¹⁰₈₄Po, having a half-life of 138 days; it as used as a reference alpha emitter in the calibration of radiation counters

(physics) The major stable isotope of neon, ²⁰₁₀Ne, having ten protons and ten neutrons; it amounts to over 90% of the element in nature

(physics) A rare stable isotope of neon, ²¹₁₀Ne, having ten protons and eleven neutrons; it amounts to less than 0.3% of the element in nature

(humorous) A phrase indicating that something must be done directly without delays or deviations.

US standard spelling of 200 metres.

A phrase telling someone to pursue a path directly without deviations.

(code word, euphemistic) Casualties for transportation in the Soviet and modern Russian military. In official use, cargo 200 refers to bodies contained in zinc-lined coffins, but in a military context it may be used for dead bodies as they are transported from the battlefield.

(computing) An issue for computing and data storage situations in which time values are stored or calculated as a signed 32-bit integer, and this number is interpreted as the number of seconds since 00:00:00 UTC on 1 January 1970. Such implementations cannot encode times after 03:14:07 UTC on 19 January 2038