Acampao- this refers to judging what is considered pleasing in the rural traditions of Chile.

Acarnerado- this is a ram-like head that ideally has some degree of semi-convexness in the facial profile.

Acoso y Derribo- this refers to the sport of “heifer bowling”. This is a Spanish stock horse event in which a paired team of horses and riders chase a heifer of the bullfighting breeds with goads in hand. One rider acts as the hazer and the other uses his goad to push the hip of the heifer off to one side and make her tumble to the ground. When the heifer gets up, an appraisal of the aggressiveness of her temperament is made. The purpose of this exercise was to determine the valor of the future brood cows that will produce bulls for the bull ring.

Adornos- this word means “decorations”. However, it refers to the combined appraisal of the tail, mane (must be judged by the “gatillo” or tuft of mane over the withers) and forelock. Ideally, good “adornos” mean an abundance of thick and wavy hair.

Acuileufú- this a Mapuche word that means “up to where the river reaches”. This eventually turned into the Spanish name “Aculeo”. At Hacienda Aculeo, the Letelier family almost reached a century of breeding supremacy in the Chilean Horse breed.

Adelantado- means scout or pioneer exploring a new area, but in Spanish the term was used as a title reserved for the important military leaders of expeditions into new lands.

A la brida- this usually refers to a riding style that uses long stirrup leathers and a three-point seat by distributing the weight of the rider on the two seat bones and the ischium (crotch). The long stirrups provide full contact of the legs all the way up to inner thighs in all gaits. This riding style offers the greatest stability and the most recourse for communication with aids, as it allows for a constant vertical column of weight distribution over the center of gravity of the horse.

Al Andalusi- an Arab name that referred to all the lands in the Iberian Peninsula controlled by the Moors. Since, in their later years, they were limited to the southern part of the peninsula, this province took on the Spanish name of Andalucia.

A la jineta- this usually refers to a type of riding style that uses short stirrup leathers and a two-point forward seat when galloping or running. It was developed for use in battle, when riding over uneven terrain and where jumping takes place, as in all these circumstances there are advantages to standing in the stirrups and sustaining the posture with the grip of the inner knees.

Algarrobo- this is a thorny leguminous tree that is a variety of the vetch that is found throughout the arid regions of Chile. Its sweet, starchy pods are a source of animal feed, and it is also used to make a type of home-made beer in northern Chile. (Prosopis chilensis)

Altiplano- this is a highland plateau. In the Andes Mountains, such plateaus are usually surrounded by many mountain peaks and snow-covered volcanoes. People and animals from these areas are well adapted to high altitude conditions, as the "altiplanos" (highlands plains) are usually at around 4,000 m (13,000 ft.) a.s.l. or higher. Quinoa is one of the few grains that can be grown at this altitude, and the varieties of Festuca forages are very fibrous, unproductive and of low nutritional quality.

Amansador- this means “broncobuster” or simply refers to the individual that starts young horses. This used to be done in a very aggressive and insensitive manner much as was also the case in the western U.S.A. Now, more and more “amansadores” understand the virtues of bonding with the horse and using natural training methods.

Andadura imperfecta, paso portante, ambladura quebrada- this refers to a broken pace that is laterally symmetrical in nature. The foreleg and hind leg follow more or less the same support and suspension phase, but not in perfect unison. As a result, the broken pace is heard as four quick beats rather than two distinct ones, as would be the case in the classical pace or trot.

Andalusi type horse- this is a variety of horse type that was bred by the Moors when they occupied the Iberian Peninsula. In general, they were medium sized (1.46 m-1.52 m), light horses that were very agile and could be anything from Barb or Andalusi crossed on the stocky northern jaca mares, to Barbs crossed on more refined Iberian types, to breeding programs that were largely efforts to produce pure Barbs in Al Andalusi. The criteria were personal and varied, as it was not a breed of a defined genotype.

Apiñadero- this is an eye-shaped pen where corralero teams receive the bovine from a chute and are then required to run the heifer three times around the pen before a gate is opened so they can continue into the main section of the medialuna.

Arreglador- this is a polished horse trainer who works with horses that have already been started and to which he teaches the more refined skills.

Arriero- this is a drover that made a living by driving livestock. Oftentimes, it was in the movement from summer to winter grazing lands and vice versa. Other times, it implied people that made the trans-Andean trip taking livestock to and from Chile and Argentina.