Gigantic, Huge, a __ Effort
This page is the CodyCross answer for the clue below from Fauna and Flora, Group 171, Puzzle 3 (Binomial Nomenclature).
Question is: Gigantic, Huge, a __ Effort
and the answer is: COLOSSAL
Word Meaning:
COLOSSAL — Extremely large or on a great scale.
Definitions from Wiktionary.