Victorious describes someone who has won — won a fight, a war, a game, an election, an argument. It is an adjective, and it points at the winner: the victorious team, the victorious army, the victorious candidate. It can also describe the thing that ended in a win: a victorious season, a victorious campaign, a victorious return home. Two things to feel here. First, victorious is a big, formal, slightly grand word. English has a plain everyday word for this — winning — and most people most of the time say 'the winning team'. You use victorious when you want the win to sound important: sport reports, news headlines, history books, speeches, church songs. Nobody says 'I was victorious' after finding a parking space, unless they are joking — and people do joke with it, on purpose, because the word is so grand. That joking use is very common now. Second, victorious carries a smell of struggle. A victory is a win that cost something. So victorious fits a war, a long court case, a hard final; it fits a bit oddly on something easy. There is also a set phrase, 'come home victorious' / 'emerge victorious', which is the shape you will meet most often in reading. 'Emerge victorious' means to come out of a hard situation as the winner — it is a favourite of sports writers.