If two things are analogous, they are similar in a useful way, so you can compare them and learn something. We do not mean they are the same; we mean they work alike, or share a pattern. You might say a city’s traffic is analogous to blood moving through a body: different stuff, similar job.

If two things are analogous如果兩樣東西彼此類似，they are similar in a useful way它們的相似是有用的，so you can compare them and learn something讓你可以拿來比較、學到一些東西。We do not mean they are the same我們不是說它們一樣；we mean they work alike or share a pattern我們是說它們運作方式類似，或有共同的模式。You might say你可以說：a city's traffic一個城市的交通 is analogous to類似於 blood moving through a body血液在身體裡流動，different stuff, similar job東西不同，功能類似。

It is a fairly formal, school-and-essay word.

It is它是 a fairly formal, school-and-essay word一個滿正式、學校和作文裡會用的字。

In biology there is a tighter sense, nearly as old as the general one: analogous parts of animals look or work alike but did not come from the same ancestral part (a bird’s wing and a butterfly’s wing).

In biology在生物學裡 there is a tighter sense有一個比較嚴格的意思，nearly as old as the general one幾乎跟一般的用法一樣古老：analogous parts of animals動物身上同功的部位 look or work alike看起來或運作起來很像 but did not come from the same ancestral part但並不是來自同一個祖先部位 (a bird's wing and a butterfly's wing)（例如鳥的翅膀和蝴蝶的翅膀）。

Scientists contrast that with homologous, which means the parts do share an origin. Everyday speakers often skip this contrast and just mean “similar enough to compare.”

Scientists contrast that with homologous科學家會拿這個字跟homologous（同源）做對比，which means the parts do share an origin意思是這些部位確實有共同的起源。Everyday speakers often skip this contrast一般人說話常常跳過這層對比，and just mean "similar enough to compare"只是想表達「相似到可以拿來比較」。