The small flakes of dried, dead skin, left behind by (usually chaffed) testicles in underwear.
"Nadruff" can also be a mixure of debris such as chad particles, semen, urine and other bodily /non bodily fluids that have dried out and crusted off.
*GIRL* licks guys testicles/nut sacks
*GIRL* Omg i got something in my mouth from your balls and its kind of chewy.
*GUY* Oh shit i must have nadruff!.
"BRO my balls are kinda itchy" , ...
"Haha, last time my nuts were itchy i went to have a wank an seen that there was "Nadruff" in my boxers!"
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 man will 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"