One way to hold it: a buster is whatever bursts the thing in front of it. Put a word before it and that word is the target — crime, a budget, a bunker — and the buster is what goes at it and breaks it open. The word aimed at a man works on the same volume: it is loud, it lands hard, and it refuses to use his name.
The source records buster as originally a dialectal variant of burster, later influenced by bust + -er. It also notes that the compound pattern was especially prolific in three periods: the 1930s (the radio series Gang Busters), the 1940s (military slang), and the 1980s (the film Ghostbusters).
資料寫的是：buster 本來是 burster（把東西撐破的人）的方言變體，後來受到 bust 加 -er 的影響。它也提到這個複合字模式特別旺盛的三個時期：一九三〇年代的廣播劇 Gang Busters、一九四〇年代的軍中俚語，以及一九八〇年代的電影 Ghostbusters。
Wiktionary (English 'buster'), etymology_text supplied in the evidence packet
Two branches
把某件事打破、終結的那一個
這一支就是核心畫面本身：前面是目標，後面是把它打破的人或東西。
noun · C1
'-buster' is added to the end of a noun to name a person, team or thing whose job is to break, stop or get rid of whatever the first word names: a crime-buster goes after crime, a bunker buster is a bomb built to break through a bunker.
終結某事的人或物
衝著一個男人叫出去
同樣的力道，只是這次不是打破東西，而是往一個人身上丟過去。資料把這個稱呼放在「了不起的大傢伙」那個舊意思底下，所以兩者是相連的，但那是資料呈現的層次，不是確定的歷史。
noun · C1
Used when speaking straight at a man who is annoying you or whom you do not respect, as in 'Listen, buster.' The source marks it spoken and American English, and it usually sounds sharp.
喂，你這傢伙