I understand that for the noun "patent", the word is pronounced as ˈpæt(ə)nt in British English and ˈpeɪt(ə)nt in American English.
However, a friend blew my mind yesterday and claimed that it could be pronounced as ˈpæt(ə)nt in American English if it was the adjective form.
I've looked on here and it seems like definitions 4, 5 and 6 of Entry 1 is indeed pronounced as ˈpæt(ə)nt but it does not mention if that is in American or British English.