jinx
Bad luck that people think is caused by someone or something.
A jinx is bad luck that seems to follow someone or something, or the act of causing that bad luck (often unintentionally). When a baseball team hasn't won a championship in decades, fans might talk about a jinx on the team. When you're about to succeed at something and someone mentions your success too early, they might worry they've jinxed it by speaking too soon.
The idea of a jinx comes from the superstitious belief that mentioning something good before it happens can somehow make it go wrong. If you're bowling and get nine strikes in a row, your friends might stay quiet about the possibility of a perfect game, not wanting to jinx your streak. Many athletes have lucky rituals they follow to avoid jinxing themselves.
Kids often play a game called “jinx” when two people say the same thing at exactly the same time. The first person to say “jinx!” gets to declare that the other person can't speak until someone says their name. This playful version turns the word into a fun competition rather than something to worry about.
While jinxes aren't real in any scientific sense, people still use the word to describe patterns of bad luck or the nervous feeling that talking about success too early might spoil it.