Abbreviation of standard. / Abbreviation of standard deviation.

Alternative form of std (“standard”)

(medicine) Initialism of sexually transmitted disease. / (telephony) Initialism of subscriber trunk dialling or subscriber toll dialing. / Initialism of short-term disability.

plural of STD

(computing) Standard output: a stream mapped to the primary output device, typically a screen.

(computing) Standard input: a stream mapped to the primary input device, typically a keyboard.

(computing) Standard error: a stream to which error messages are sent, often the same stream as stdout.