To baa is to make the noise a sheep makes; as a noun, a baa is that noise. Small children learn it as the farm-animal sound, the way they learn moo for a cow. Adults use it too, usually with a smile, or when they are talking to a child.

To baa當動詞baa is to make the noise a sheep makes就是發出羊叫的聲音 as a noun當名詞用 a baa is that noise指的就是那個聲音。Small children learn it小孩子學這個字 as the farm-animal sound當成農場動物的叫聲 the way they learn moo for a cow就跟他們學牛叫moo一樣。Adults use it too大人也會用 usually with a smile通常帶著微笑 or或 when they are talking to a child是在跟小孩講話的時候。

The word does not hide a smaller word inside it: people copied the noise. German has close cousins of that copy, bäh and mäh.

The word does not hide a smaller word inside it這個字裡面沒有藏著別的字根 : people copied the noise人們單純就是模仿了那個聲音。German has close cousins of that copy德文也有很接近的模仿字 bäh and mäh就是bäh和mäh。

Though actually, English has not stood still. Speakers once said this word with a flatter vowel, closer to the sheep. That vowel later moved back in the mouth — a slow change in English in the 1700s and 1800s — so ‘baa’ on the page is a slightly faded copy of the noise. Something similar happened when older ‘mew’ for a cat gave way to ‘meow’.

Though actually不過 English has not stood still英文並沒有一直不變。Speakers once said this word以前的人講這個字 with a flatter vowel母音比較扁 closer to the sheep更接近羊叫聲。That vowel later moved back in the mouth這個母音後來在口腔裡往後移了 a slow change in English in the 1700s and 1800s這是英文在十八、十九世紀慢慢發生的變化 so所以 'baa' on the page書面上的「baa」 is a slightly faded copy of the noise其實是那個聲音一個有點褪色的模仿。Something similar happened類似的事也發生過 when older 'mew' for a cat gave way to 'meow'以前貓叫的「mew」後來被「meow」取代。

Informal, slightly childlike in tone, but not only a children’s word.

Informal這個字不正式 slightly childlike in tone語氣有點孩子氣 but但 not only a children's word卻不是只有小孩才用。