Manx, oryx, onyx, jinx, linx, Styx, Knox, flax.
A four letter word beginning with C and ending with X is crux.
Try flux or flax; latter is healthier.
STIX !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Could be a four letter word that starts with s and ends with x
Four letter words with X as the third letter:boxyfoxyluxenextpoxysexytaxitextwaxy
Flax.
cortex
Five letter words starting with C and ending with X are calyx and codex.
phoenix?
x-ray
Pheonix
The word faux has a silent x, pronounced [foh].
Faux Hoax That's all I know