A stinker is something or someone that's unpleasant or annoying.
You might hear people use this word when talking about a smell. For example, if someone leaves their trash out and it starts to rot, people will say "That's a real stinker!" But the word can also be used to describe an idea or situation that nobody likes. Imagine you're planning a party and one of your friends suggests doing something boring - in this case, the activity would be a stinker. The word can even be used as a verb, meaning to spoil or ruin something. So if someone says "You just had to go and stink up our good time," they mean you did something that made things unpleasant.
A person who stinks.
