A tightrope is a tightly stretched rope or cable suspended high above the ground, used for acrobatic performances. A tightrope walker carefully balances while crossing from one end to the other, placing one foot directly in front of the other with intense concentration. One wobble could mean a dangerous fall, which is why tightrope walkers often use a long pole to help maintain their balance, and why circus performances include safety nets below.

The most famous tightrope walker in history was probably Philippe Petit, who in 1974 secretly strung a cable between New York's Twin Towers and walked between them 1,350 feet in the air, with no safety net. Tightrope walking (also called funambulism) requires extraordinary balance, courage, and thousands of hours of practice.

People also use tightrope as a metaphor for any difficult situation requiring extreme care and balance. A teacher might walk a tightrope between being friendly and maintaining classroom discipline. A diplomat might walk a tightrope between two countries with opposing interests. When someone says they're walking a tightrope, they mean they're in a delicate situation where one wrong move could lead to serious trouble.