to go without wearing any underwear under ones out clothes (distinguished by is being applicable to both genders as opposed to freeball which is used exclusively for males)
I do not think I could go commando on a regularbasis. I could not get used to it.
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.