colossalyoudaoicibaDictYouDict[colossal 词源字典]
colossal: [18] Colossal comes ultimately from Greek kolossós, a word of unknown origin which was first used by the historian Herodotus as a name for certain gigantic statues in Egypt. It became much better known, of course, when applied to the Colossus of Rhodes, a 36-metrehigh statue of Apollo that stood at the entrance to Rhodes harbour, built around 280 BC. Various adjectives meaning ‘huge’ have since been derived from it: Latin had colossēus and colossicus, and in the 17th century English tried colossean and colossic, but in the 18th century the choice fell on colossal, borrowed from French.

The amphitheatre built in Rome by Vespasian and Titus around 80–75 BC was named Colossēum after its great size.
[colossal etymology, colossal origin, 英语词源]
colossal (adj.)youdaoicibaDictYouDict
1712 (colossic in the same sense is recorded from c. 1600), from French colossal, from colosse, from Latin colossus, from Greek kolossos (see colossus).