dragonyoudaoicibaDictYouDict[dragon 词源字典]
dragon: [13] English acquired dragon via Old French dragon and Latin dracō from Greek drákōn. Originally the word signified simply ‘snake’, but over the centuries this ‘snake’ increased in size, and many terrifying mythical attributes (such as wings and the breathing of fire) came to be added to it, several of them latterly from Chinese sources. The Greek form is usually connected with words for ‘look at, glance, flash, gleam’, such as Greek drakein and Sanskrit darç, as if its underlying meaning were ‘creature that looks at you (with a deadly glance)’. Dragon is second time around for English as far as this word is concerned: it originally came by it in the Old English period, via Germanic, as drake. Dragoons [17] (an adaptation of French dragon) were originally mounted infantry, so called because they carried muskets nicknamed by the French dragon ‘fire-breather’.
=> dragoon, drake, rankle[dragon etymology, dragon origin, 英语词源]
dragon (n.)youdaoicibaDictYouDict
early 13c., from Old French dragon, from Latin draconem (nominative draco) "huge serpent, dragon," from Greek drakon (genitive drakontos) "serpent, giant seafish," apparently from drak-, strong aorist stem of derkesthai "to see clearly," from PIE *derk- "to see." Perhaps the literal sense is "the one with the (deadly) glance."

The young are dragonets (14c.). Obsolete drake "dragon" is an older borrowing of the same word. Used in the Bible to translate Hebrew tannin "a great sea-monster," and tan, a desert mammal now believed to be the jackal.