The initials LSD can have several meanings:
- LSD is the drug lysergic acid diethylamide. LSD is an acronym of the German language name for the compound, Lyserg-Säure-Diaethylamid.
- LSD was the abbreviation for the old British currency units: pounds, shillings, and pence, from the Latin librae, solidi, and denarii, prior to decimalisation. Values were written like for example £12 10s. 6d., meaning twelve pounds, ten shillings, and sixpence. In informal speech, "LSD" was often used to mean "money". See pound (sterling)
- LSD is the US Navy hull classification symbol for Dock Landing Ship.
- In statistics, LSD is an abbreviation for Least Significant Difference.
- LSD stands for \limited slip differential in automobile engineering
- The French rock and roll band La Sourie Deglinguee is sometimes called LSD.