Initialism of South Dakota. / (uncountable) Initialism of Secure Digital: a non-volatile memory card format developed for use in portable devices.

Initialism of school district. / (law enforcement) Initialism of sheriff's department. / (mathematics) Initialism of standard deviation. / (video games) Initialism of self-destruct.

(television) Initialism of standard definition (“typically 640×480 pixels”).

(Britain, historical after 1971) pounds, shillings, pence / (Britain) money in general

Alternative letter-case form of SD, standard deviation

plural of sd

(UK, historical) Initialism of Special Demonstration Squad. / (US, historical) Initialism of Students for a Democratic Society.

(organic chemistry) Initialism of sodium dodecyl sulfate. / Initialism of safety data sheet.

plural of SD

A type of non-volatile memory card.