The Collaborative International Dictionary
Apiol \A"pi*ol\, n. [L. apium parsley + -ol.] (Med.) An oily liquid derived from parsley.
n. (context organic chemistry English) A particular aromatic compound found in parsley
Apiol, also known as 'liquid apiol' or 'green oil of parsley' is the extracted oleoresin of parsley, rather than the distilled oil. Due to its similarity to the term apiole, care should be taken to avoid confusion. Apiol is an irritant and, in high doses, it can cause liver and kidney damage. Cases of death due to attempted abortion using apiol have been reported.
Its use was widespread in the US, often as ergoapiol or apergol, until a highly toxic adulterated product containing apiol and tri-ortho-cresyl phosphate (also famous as the adulterant added to Jamaican ginger) was introduced on the American market.
Now that safer methods of abortion are available, apiol is almost forgotten.