'Sinistro' is a carioca's slang that could means st. cool or st. really bad. It depends on the emphasis.
ex.: Man, the party last night was 'sinistro'. (cool)
ex.: So, it seems the accident was 'sinistro'. (terrible)
ex.: So, it seems the accident was 'sinistro'. (terrible)
by Antonio Proenca March 17, 2007