What is a Promise Ring. A promise ring, sometimes known as a pre-engagement ring, is a simple piece of jewelry that is given as a symbol of a committed, monogamous relationship. In some cases, the promise ring symbolizes purity and a decision to remain celibate until marriage.
Noun. 1. external respiration-the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation. breathing, respiration, ventilation. artificial respiration-an emergency procedure whereby breathing is maintained artificially.
External Respiration. External respiration is the process wherein animal life receives air from the environment and in a gaseous exchange returns the air to the environment in another form. This gaseous exchange takes place in all life forms, from insects to fish to human beings to plants, including algae and fungus.