In the manner or fashion of a colossus; in a gigantic, monumental, or impressive way.
Compound word combining 'colossus' with the Old English suffix '-wise' (meaning 'in the manner of'). This suffix was productive in English for creating adverbs describing how something was done.
The '-wise' suffix is ancient—people used it constantly centuries ago to turn nouns into adverbs, like 'clockwise' or 'likewise'—but it's fading from common speech, making 'colossuswise' a beautiful fossil word from an older way of English.
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