Wiktionary
gamma-butyrolactone
n. (context chemistry pharmacology English) The lactone of 4-hydroxybutyric acid; A colourless liquid used as a solvent or reagent in various industrial uses, as well as a recreational drug. Abbreviated to '''GBL'''.
Wikipedia
Gamma-Butyrolactone
γ-Butyrolactone (GBL) is a hygroscopic colorless liquid with a weak characteristic odor. Soluble in water, GBL is a common solvent and reagent in chemistry as well as being used as a flavouring, as a cleaning solvent, as a superglue remover, and as a solvent in some wet aluminium electrolytic capacitors. In humans it acts as a prodrug for γ-hydroxybutyric acid (GHB), and it is used as a recreational intoxicant with effects similar to alcohol.