Tenuous means weak, slight, or barely holding together. When something is tenuous, it's fragile and could easily break apart or disappear.

A tenuous connection between two ideas means they're only loosely related, like claiming that because you both like pizza, you must also share the same taste in music. A tenuous friendship might fade away quickly because it was never very strong to begin with. Scientists sometimes describe evidence as tenuous when it's thin or uncertain, not solid enough to prove their theory.

The word often describes things that seem like they might not last. A tightrope walker's grip on a slippery rope is tenuous. An excuse that barely makes sense is tenuous. When a sports team has only a tenuous lead, they're ahead by just a point or two, and the other team could easily catch up.

You might hear someone say a theory rests on tenuous assumptions, meaning it's built on shaky ideas that might not be true. Or that a politician has only a tenuous grasp of the facts, suggesting their understanding is weak and incomplete. When something is tenuous, it needs strengthening, or it might not hold up under pressure.