Start with a sound, not a meaning. Someone laughs, and English the sound straight down: ha-ha. Everything else here is that sound being moved around. Count it and it becomes a thing you can have several of — a few ha-has from the next room. Point at whatever pulled the sound out of you and that gets the name too — a film with a few good ha-has. Say it with no laugh behind it and the empty sound tells the other person that nothing here was funny.
可以想成：這個字一開始不是一個意思，而是一個聲音。有人笑了，英文就把那個聲音原封不動寫下來——ha-ha。後面所有用法，都是這個聲音被搬到不同位置。把它拿來數，它就變成一件件的東西：隔壁傳來幾聲 ha-has。把名字送給「引出這個聲音的東西」，它就變成笑點：a few good ha-has。而如果把聲音講出來、裡面卻空空的沒有笑意，對方聽到的就是相反的訊息：我不覺得好笑。
From the word’s history
Wiktionary's etymology for this entry is simply 'Imitative' — the word is the sound of laughing, written down.
本批 Wiktionary 的詞源說明只寫 imitative（擬聲）：這個字就是把笑聲寫成文字，沒有別的來源。所以它的核心一直都是那個聲音本身。
Wiktionary, "ha-ha" (etymology 1)
登入就可以看每一支怎麼連回核心畫面。