How many letters does the top answer for “a principle, or mixture of principles, derived from various species of euphorbia.” have?

The most common answer is euphorbin (9 letters).

Crossword clue: a principle, or mixture of principles, derived from various species of euphorbia.

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

euphorbin 9 letters web-def

A principle, or mixture of principles, derived from various species of Euphorbia.

euphorbine 10 letters web-def

A principle, or mixture of principles, derived from various species of Euphorbia.