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!
A normal Human being should have a balanced behavior. It not uncommon for someone to criticize someone else or to be sarcastic every once in a while but when the critical comments start to flood everyone surrounding the person and when their sarcastic behavior starts to hurt the close ones then they are in need of help.