Bell-bottoms (or flares) are a style of trousers that become wider from the knees downward, forming a bell-like shape of the trouser leg.
In the 1960s, bell-bottoms became fashionable for both men and women in Europe and North America. Often made of denim, they flared out from the bottom of the calf, and had slightly curved hems and a circumference of 18 inches (46 cm) at the bottom of each leg opening. They were usually worn with Cuban-heeled shoes, clogs, or Chelsea boots.
In the 1970s, bell-bottoms moved back into mainstream fashion. The pants were typically flared from the knee down, with bottom leg openings of up to twenty-six inches. Made from denim, bright cotton and satin polyester, they were so popular that they became a symbol of the outlandish and colorful style of the decade.
Here below is a cool photo collection that shows young men in bell-bottoms from the 1970s.