1) Colorless liquid 2) Glycerol-based solvent 3) Liquid ester 4) Viscous vinegar, chemically 
• (n.) A combination of acetic acid with glycerin.
<chemical> A thick, colourless, water-attracting liquid which is used as a food additive and dye solvent and in explosives manufacture and leather tanning. It is created by heating and then distilling a mixture of acetic acid and glycerol. ... (09 Oct 1997) ... 
Ac'e·tin noun (Chemistry) A combination of acetic acid with glycerin. Brande & C. 
noun any of three liquid acetates that are formed when acetic acid and glycerin are heated together
a colorless, thick, hygroscopic liquid, CHO: used chiefly in the manufacture of explosives. Also called