On a sidenote, many speakers of English probably are unfamiliar with the pronunciation of Dutch knakken or German Knacker (ˈknakɐ, you can listen to Google Translate's rather mediocre rendition[1]). Kn in word-initial position is fairly common, and the k is not silent in these languages, nor is there an aspiration between k and n.

[1] https://translate.google.com/?sl=de&tl=en&text=Knacker%0A&op...