Hair by hair; one hair at a time; used figuratively to mean doing something painstakingly or in very small increments (as in the phrase "pelo a pelo").
4.
SpainLatin Americaneutral
Having the smell or quality of burnt hair (literal descriptive use).
5.
SpainLatin Americacolloquial
Without protection, covering, or equipment; exposed or unprotected (generalized figurative extension of the literal senses).
Examples:
ES: ¡Hubiera montado a pelo!
EN: He'd have been riding bareback!
ES: Pues que hubiera montado a pelo.
EN: Why, he would've been riding bareback.
ES: Tratado, pelo a pelo.
EN: Stuck on hair by hair.
ES: El mujerío de por aquí usa sombreros abiertos y las jóvenes van a pelo.
EN: Women folks around here wear split bonnets. The young ones goes bareheaded.
ES: ¡Huele a pelo quemado!
EN: Smells like burning hair.
ES: Siempre quise ver a un inglés montar un caballo a pelo.
EN: Well, I always wanted to see an Englishman ride a bucking horse.
ES: El motivo de ello, es que les será más fácil montar a pelo.
EN: The reason it has no saddle is because it will be easier for you to stay on without the saddle.
ES: Después del circo, nada superaba a la amazona que montaba a pelo.
EN: After the circus, you thought... the bareback rider was the most beautiful thing in the world.
ES: "Derribar un becerro, 50 dólares... montar a pelo 25, doma, 20..."