Definition of puff out

The phrase "puff out" originated in the mid-17th century and originally referred specifically to the blowing of feathers out of a pillow or cushion to make it fluffier and more comfortable to sit on. The word "puff" itself comes from the Old Norse word "pusta," meaning to blow or inflate, and was borrowed by Middle English around the 13th century. In its original context, "puff out" described a physical action, but by the 18th century, it began to take on more figurative meanings. People started using it to describe how birds and animals would fluff out their feathers or fur in a similar way to make themselves appear larger and more intimidating to potential predators or competitors. Over time, "puff out" has been extended to describe a variety of ways people and animals might make themselves larger or more prominent, from puffing out one's chest in pride or confidence, to inflating oneself with gas in order to become lighter and able to stay aloft, as with some birds. Today, "puff out" remains a vivid and evocative expression, suggesting both physical expansion and a swell of pride, confidence, or aggression, and continues to be used widely in both spoken and written language.