A Doublet: A pair of similar things, in particular two words of the same derivation but having different meanings.
终极词源相同，但由于演变路径不同，而形、音、义上有所不同的词。
源头一般是拉丁语，演变路径通常分两条，一条直接从拉丁语被进入英语，另一种先被引入法语/意大利语/德语，再进入英语。虽然说殊途同归，但最终的词义，用法和习语搭配都不用。
Etymology
late 14 c. , from Gk. etymologia , from etymon "true sense" ( neut. of etymos "true," related to eteos "true") + logos "word…
Frail & Fragile
🎴 单词frail和fragile（易碎的）是一对 同源异形词 ，即终极词源相同，但由于演变路径不同，而形、音、义上有所不同的词。fragile直接来自拉丁词或经法语进入英语，而frail则经古法语进入。 Word Comparison
Intrigue & Intricate
🎴 There is an intriguing link between intrigue and intricate (Late Middle English). Both ultimately derive from Latin intricare ‘to…
Money
🎴 In ancient Rome money was coined in a temple to the goddess Juno, where she was identified with a pre-Roman goddess called Moneta and…
Regal & Royal
🎴 拉丁语rex，意为“君王”。历史上以不同途径两次被引入英文：第一次原装进口，从rex直接变为英语Regal；第二次借道法国，先被写为古法语roial，再进入英语写为Royal。 Regal和Royal 同根且同义 ，然而法版Royal…
Sure & Secure
🎴 This is from Old French sur , from Latin securus ‘free from care’. The same Latin word gives us security (Late Middle English), the…