Sheer describes something so thin you can see through it, or something complete and total. When a curtain is sheer, light passes through the delicate fabric. When a cliff face is sheer, it drops straight down without any gentle slope.

The word often emphasizes how extreme or absolute something is. A sheer drop means straight down with nothing to grab onto. Sheer luck means pure chance with no skill involved. Sheer determination means willpower so complete that nothing else matters. If you accomplish something through sheer effort, you succeeded by working incredibly hard, not because you had special advantages or lucky breaks.

In another sense, sheer means to swerve or change direction suddenly. A car might sheer off the road, or a boat might sheer away from rocks. You'll see this meaning less often, but it appears in stories about vehicles or ships avoiding danger at the last moment.