The word faux has a silent x, pronounced [foh].
Five letter words starting with C and ending with X are calyx and codex.
There are no commonly used words in English where the letter "o" is silent. However, there may be some words borrowed from other languages, like "doux" in French, where the "x" is pronounced instead of "ou".
box, fox, ibex
anthrax
orthodox
fox vox box pox
The word faux has a silent x, pronounced [foh]. The word anxiety has a silent x,pronounced[ansiety]
The silent letter in "xylophone" is the "x." It is pronounced as "zy-lo-phone."
Lunchbox, ox, fox, lox. helix.
There's lynx, minx, Styx, and jinx.
Calyx, codex and cylix are 5 letter words. They begin with c and end with x.
Fix, Nix, Tax, Crux, Lax, Mix