glu·tar·al·de·hyde 
(gl′tə-răldə-hīd′)
(gl′tə-răldə-hīd′)n.
A water-soluble oily liquid, C5H8O4, containing two aldehyde groups, used in tanning leather and as a fixative for biological tissues.
[glutar(ic acid), organic compound used in making polymers (GLUT(EN) + -aric, probably as in TARTARIC ACID) + ALDEHYDE.]