Directly related words:
* Colossal: (adjective) extremely large; gigantic.
* Colossally: (adverb) in a colossal manner; extremely.
* Colossean: (adjective) of or relating to a colossus or something colossal.
Related words with similar meaning:
* Gigantic: (adjective) huge; enormous.
* Immense: (adjective) extremely large; vast.
* Monumental: (adjective) very large or impressive.
* Massive: (adjective) very large and heavy.
* Enormous: (adjective) very large in size or extent.
* Mammoth: (adjective) huge; gigantic.
Less directly related but with a similar sense:
* Colossal squid: A species of squid known for its enormous size.
* Colossal titan: A term used to describe a very large and powerful individual.
* Colossal order: A style of architecture featuring giant columns and a wide, flat cornice.
It's important to remember that words like "gigantic," "enormous," etc., are not directly derived from "colossus" but share a similar meaning and are often used in place of "colossal."