Esters, ethers, and other O-derivatives of glycerol with alkyls or alkenyls, including mono-, di-, and tri-substituted glycerols.
Examples: 1-dodecanoyl-sn-glycerol (monoacylglycerol), 1-dodecanoyl-2-hexadecanoyl-3-octadecanoyl-sn-glycerol (triacylglycerol).
Source:
PAC, 2018, 90, 1121. 'Terminology of bioanalytical methods (IUPAC Recommendations 2018)' on page 1177 (https://doi.org/10.1515/pac-2016-1120)