The Collaborative International Dictionary
Leuc-
Leuco- \Leu"co-\ (l[=u]"k[-o]-), Leuc- \Leuc-\ (l[=u]k-). pref. A combining form signifying white, colorless; specif. (Chem.), denoting an extensive series of colorless organic compounds, obtained by reduction from certain other colored compounds; as, leucaniline, leucaurin, etc.
Leuc-
Leuc- \Leuc-\ (l[=u]k-) pref. Same as Leuco-.