The thesaurus of synonyms and related words is fully integrated into the dictionary. Click on the thesaurus category heading under the button in an entry to see the synonyms and related words for that meaning. Past participles:arisen, been, befallen... This is the British English definition of striven.
Personally, sarcasm can mean a couple of things depending on how it is dealt out. If it is sarcastic in a funny way, that person may have a sense of humor. If it is said in a mean way, than that person is probably insecure and unhappy. IMHO!
In essence, sarcasm is easy (as is most anger, criticism and meanness) while true, harmless wit takes talent. Thus, the main difference between wit and sarcasm is that, as already stated, sarcasm is hostility disguised as humor. It is intended to hurt, and is often bitter and caustic.