Greek Strong's Dictionary with all the Synonyms inserted into the definitions.
Greek Synonyms inserted into Greek Strong's Dictionary
4557 + sardonyx +/ . sardonux {sar-don'-oox}; from the base of 4556 + sardius +/ and onux (the nail of a finger; hence the "onyx" stone); a "sardonyx", i .e . the gem so called: --sardonyx .