Information that can be dangerous to know about. Some examples are how locking your knees too hard can cut off circulation and be lethal, or how grabbing your thumb and shaking your wrist can break an important part of your thumb. Yes, obviously there are much more dangerous things to know about, but that's up to you I guess.
Totally real person 1: Have you heard that grabbing your thumbs and shaking your wrists can break your thumb?
Totally real person 2: That's an infohazard
Someone or something that bites your ankles.
To a postman, an ankle biter is often known as a dog.
To an adult, an ankle biter may be a toddler.
To hikers, an ankle biter is sometimes a tick.
And so on.
When a manwill search for hours to find something that is laying out in the open on a table. Items are often easily found by a women.
Man: "I have been searching for hours for keys."
Woman: "You mean the ones sitting there on the coffee table?"
Man: "Where?"
Woman: "Right there in the middle of that table."
Man: "oh, must have been Male Pattern Blindness"