It`a·con'ic adjective [ From
aconitic , by transposition of the letters.]
(Chemistry) Pertaining to, or designating, an acid, C
5 H
6 O
4 , which is obtained as a white crystalline substance by decomposing aconitic and other organic acids.
Found on http://www.encyclo.co.uk/webster/I/104

• (a.) Pertaining to, or designating, an acid, C5H6O4, which is obtained as a white crystalline substance by decomposing aconitic and other organic acids.
Found on http://thinkexist.com/dictionary/meaning/itaconic/
No exact match found