2 language factoids.

"Curtsy" is related to "court" (so I heard today, haven't had time to check this out).

"Floyd" is the same name as "Lloyd", since Welsh devoices /l/ sometimes, and so when this happened, people heard the devoiced /l/ as an /f/.

(If you put your hand over your throat and say /z/ and /s/, feel how /z/ has your throat vibrate in a way that /s/ doesn't; now say an /l/ and try not to have your throat vibrate like /s/ as opposed to /z/, and if that happens, you'll likely hear the sound as something like an /f/.)