Defn: A genus of herbs, some species of which, especially the Isatis tinctoria, yield a blue dye similar to indigo; woad.

ISATOGEN
I*sat"o*gen, n. Etym: [Isatin + -gen.] (Chem.)

Defn: A complex nitrogenous radical, C8H4NO2, regarded as the essential residue of a series of compounds, related to isatin, which easily pass by reduction to indigo blue. — I*sat`o*gen"ic, a.

ISATROPIC
I`sa*trop"ic, a. Etym: [Is- + atropine.] (Chem.)

Defn: Pertaining to, or designating, an acid obtained from atropine, and isomeric with cinnamic acid.

ISCHIAC
Is"chi*ac, a. (Anat.)

Defn: See Ischial.

ISCHIADIC
Is`chi*ad"ic, a. Etym: [L. ischiadicus, Gr. Sciatic.] (Anat.)

Defn: Ischial. [R.] Ischiadic passion or disease (Med.), a rheumatic or neuralgic affection of some part about the hip joint; — called also sciatica.

ISCHIAL
Is"chi*al, a. (Anat.)