LSD

noun

ˌel-(ˌ)es-ˈdē 

: a semisynthetic illicit organic compound C₂₀H₂₅N₃O derived from ergot that induces extreme sensory distortions, altered perceptions of reality, and intense emotional states, that may also produce delusions or paranoia, and that may sometimes cause panic reactions in response to the effects experienced

called also lysergic acid diethylamide

Examples of LSD in a Sentence

Recent Examples on the Web

On Matador Beach in Malibu one night, Leary taught Marin all about the stars and constellations while the LSD took hold. —Will Yakowicz, Forbes.com, 24 Aug. 2025

The chemicals in mushrooms and LSD are less toxic, and rarely lethal on their own, but both drugs can impair judgment and mood in ways that can lead to injury or death. —Andre Mouchard, Oc Register, 18 Aug. 2025

But in the long term, evidence is mounting that the shift away from gut-busting hero workouts and towards what used to be called LSD—that’s long, slow distance—is a smart one. —Alex Hutchinson, Outside, 18 Aug. 2025

This week brings three very different examples of the genre: Silversun Pickups at Toad’s Place and a double bill of LSD and the Search for God and Her New Knife at Space Ballroom. —Christopher Arnott, Hartford Courant, 16 Aug. 2025

Word History

Etymology

borrowed from German, from Lysergsäure-Diäthylamid "lysergic acid diethylamide"

First Known Use

1950, in the meaning defined above

Kids Definition

LSD

noun

ˌel-ˌes-ˈdē 

: an illegal drug that causes abnormal sensations, extreme and changeable states of emotion, unnatural changes in the way time and space are experienced, and hallucinations and that may sometimes cause panic in response to the effects experienced

Medical Definition

LSD

noun

ˌel-ˌes-ˈdē 

: a semisynthetic illicit organic compound C₂₀H₂₅N₃O derived from ergot that induces extreme sensory distortions, altered perceptions of reality, and intense emotional states, that may also produce delusions or paranoia, and that may sometimes cause panic reactions in response to the effects experienced

called also acid, lysergic acid diethylamide, lysergide